Pros and cons of X12MF steel for knives, key characteristics

The best Russian masters of damask knives

It is believed that products made of alloy steel compete with damask knives in the modern market.
But is this really so, and are there craftsmen in Russia today capable of making forged knives that have no equal in quality? It turns out there is. The secret of high-quality damask steel is held by such masters as I. Pampukha and A. Biryukov. Their products are famous not only in Russia, but also abroad. Blacksmith I. Pampukha has been famous in Russia for his knives made of damask and Damascus steel for almost two decades. A master blacksmith in the third generation, he is one of the few who keeps the secret of real damask steel and follows all the necessary technologies for forging, casting and sharpening. His stainless steel knife, made using modern technology, retains the properties of classic steel and is highly resistant to corrosion. His hunting knives, having passed the test for cutting and blade strength upon impact, showed that the damask steel of his production is much superior to the alloy steel of knife blades from leading manufacturing companies. The knives of I. Pampukha also deserve the title of highly artistic execution. For the handles, the master chooses not only such expensive materials as walrus tusk and ebony, but also decorates them with precious stones and mother-of-pearl inlay.

Andrey Biryukov's forge is also famous for its tradition of high-quality damask knives, which are distinguished by high cutting quality and resistance to corrosion. However, not only these qualities, but also quite reasonable prices make them popular among damask steel lovers. Such private craftsmen as S. Baranov, S. Lunev and the Arkhangelsky family make blades from Damascus steel with fairly high quality and reasonable prices, but they are still inferior to the products of I. Pampukha in durability and cutting, and are more suitable for collecting or for use in everyday life. For example, in the kitchen.

Mechanical properties

Characteristics and properties of steel x12MF

Steel acquires special characteristics as a result of the addition of alloying elements, when certain temperature conditions, the number of hardenings, and so on are set. The characteristics of x12MF are determined by the special composition of the elements:

• carbon (C): 1.45−1.65;
• vanadium (V): 0.15−0.30;
• silicon (Si): 0.10−0.40;
• copper (Cu): no more than 0.30;
• molybdenum (Mo): 0.40−0.60;
• manganese (Mn): 0.15−0.45;
• nickel (Ni): no more than 0.35;
• phosphorus (P): 11.00−12.50;
• sulfur (S): no more than 0.030.

It is these elements in a given quantity, subject to the standards of the technological process of steel production, that give it the following properties:

• strength;
• increased corrosion resistance, durability;
• cutting ability.

has a number of advantages

Ordinary consumers are of little interest in a set of dry numbers, what the actual characteristics of the x12MF are, but experts immediately see their practical significance. After all, it is the beneficial properties and characteristics of the material that indicate the areas where steel of this quality can be used.

CHEMICAL COMPOSITION OF TOOL STEEL X12MF

• Chromium (Cr). Content 11 – 12.5%. Chrome increases wear resistance and cutting properties. Makes metal resistant to corrosion.
• Carbon (C). Content 1.45 – 1.65%. Gives steel hardness and durability, increases the resistance of the alloy during heat treatment, and also makes it more durable.
• Molybdenum (Mo) - 0.40 - 0.60%, Vanadium (V) - 0.15 - 0.30%. Silicon (Si) - 0.10 0.40%. Steel is hardened in deep layers thanks to this element.
• Manganese (Mn) – 0.15 – 0.45%. Thanks to it, the alloy is less deformed during hardening.
• Nickel (Ni) - no more than 0.35% and Copper (Cu) - no more than 0.30%. The content of elements in the composition of steel prevents carbon from reacting with other components and improves ductility, and also eliminates brittleness during tempering.
• Phosphorus (P) allows metal to be cast smoothly during the annealing stage and improves ductility. Its content for high-quality steel should be no more than 0.030%.

Chemical composition

This X12MF steel is very diverse in composition and is rich in different types of metals. It has no analogues among other alloys. The following is the chemical composition of X12MF:

• Chrome – 12%. Added to improve cutting properties and wear resistance.
• Molybdenum - 0.6%. The viscosity and hardenability of the metal increases. If the concentration is too high, the durability decreases.
• Carbon - 1.6%. Gives hardness. Steel becomes wear-resistant.
• Vanadium - 0.3%. Reduces the sensitivity of steel to overheating.
• Silicon – 0.4%. Provides resistance to tempering during heat treatment.
• Copper – 0.3%. Strengthening.
• Manganese – 0.45%. When manganese is added, the alloy is less subject to warping when it is hardened.
• Nickel 0.35%. Prevents the formation of carbides.
• Phosphorus – 12%. Adds plastic qualities.
• Sulfur – 0.3%. Improves elasticity.

The percentage is indicated in the maximum values ​​​​of its presence in steel. In fact, it can range from one tenth to four tenths of a percent of a given metal content. Each of the metals affects a certain property of X12MF.

Mechanical characteristics

In terms of mechanical characteristics, X12MF steel has the following advantages:

• High strength.
• Good cutting ability.
• High corrosion resistance.
• Durability.

Alloy steel X12MF is created in strict accordance with GOST and TU requirements.

Technological properties

Steel is an alloy of carbon and iron. And this alloy is made by adding many more metals, which were listed above. Therefore, X12MF is very capricious in processing. Characteristics of X12MF:

• Hard to forge.
• It is subjected to complex heat treatment, since it is necessary to maintain extremely precise temperatures of tempering, holding and other parameters.
• It is hardened at a temperature of 950 degrees Celsius. Overheating should not be allowed. Since excessive temperature greatly affects the structure of the alloy, making it more brittle.
• Has a hardness of up to 64 HRC.

Despite the fact that it is very difficult to make piece goods from this steel, there are still blacksmiths who make excellent knives. Thanks to the properties of steel, especially the presence of chromium (X12), the resulting products are famous for the strength and sharpness of the blade. These characteristics of Damascus steel knives allow you to instantly cut the flesh of a killed animal. For a hunter, this is simply an excellent weapon.

physical characteristics

Due to its physical properties, this grade of stainless steel X12MF is not intended for throwing or testing for bending. If during production the rules of hardening and maintaining temperature accuracy were not followed, then such an oversight will have a bad effect on the hardness of the alloy. The blade of the knife can be easily broken.

A product made from this alloy will serve its owner for a long time if two conditions are met:

• All technologies were followed during production.
• The owner carefully monitors and cares for his instrument.

And also X12MF can:

• Easy to carry out planing and polishing work (used in woodworking factories).
• Does not require frequent sharpening.
• It can easily withstand 40-degree frosts and the same heat.
• When the metal is exposed to high temperatures, the steel does not deteriorate or warp.
• Long service life. This property of this steel is due to the presence of vanadium.
• A person can sharpen the tool himself.
• Has resistance to corrosion.
• It does not break if the alloy is homogeneous in structure.

Areas of use

This type of steel and products made from it are used both in everyday life and in industry. In everyday life, X12MF is famous for its excellent and wear-resistant knife blades. Knives made of this steel can be used both at home and while hunting or fishing. Sharp steel easily cuts through delicate green shoots, reeds, and thin branches. The main thing is not to get carried away and not to cut bones with it, and not to use it as an ax. Because chips then appear on its canvas. This will ruin not only the aesthetics of the blade, but also its functionality.

Knives made from X12MF tool steel require a special approach to caring for them. The knife blade is treated with mineral oil. To sharpen or straighten it, fine-grained diamonds, leather belts and GOI paste are used. The correct sharpening angle is the basis for its sharpness and wear resistance. It is equal to thirty-five degrees in tilt.

In addition, below are some recommendations for caring for such knives:

• After use, the knife is washed under running water. Then it is wiped with a paper napkin. Because this particular product absorbs moisture well, unlike fabric. And the blade should under no circumstances be connected for a long time to water elements for apartment buildings. Since it contains chlorine, which will definitely interact with this alloy. The blade will become stained and may darken.
• In order for it to regain its original appearance, it must be lubricated with a special compound, which is sold in a gun store.
• It needs to be polished once every four months.
• Do not use a dishwasher to clean it. Otherwise, the blade may become dull or even damaged.
• It must be stored in special knives that came with it when sold.
• The wooden handle must be treated with antiseptics so that it is not damaged by bacteria and fungi, for which it is a favorite food. And, if the handle is metal, then it is necessary to eliminate chips and scratches. If rust appears in these places, it will soon reach the blade.

And in order to prove the advantage of this product made of X12MF tool steel over other products, numerous experiments were carried out. Data from which will be disclosed below. The Damascus steel blade has proven itself to be the best.

• This product was used to cut synthetic fiber ropes with a diameter of two centimeters.
• Oak bars were cut more than a hundred times.
• Numerous cans have been opened with this knife.
• The spine and bones of the boar were cut with this blade.
• The blade, under its pressure, cut the newspaper sheet lengthwise.

Bearing made of steel X12MF

Many products made from this alloy were tested. It has proven itself to be the most advanced alloy ever produced by mankind.

Industrial Applications

X12MF steel has found its application in industry. It is necessary where tools such as:

• Drawing boards.
• Forming dies.
• Bending dies.
• Bar metal calibration eyes for thread rolling.
• Sections of complex design of body dies.
• Dies for active parts of electrical machines are also made from it.
• Parts of electromagnetic systems of electrical devices.
• Bearings.
• Profile rollers.

Steel stamp X12MF

X12MF steel has proven that it is a durable, wear-resistant metal alloy that will serve humanity for a long time.

Analogs

The most famous foreign analogue of X12MF steel is grade D2. The metal is produced by the Americans; their chemical composition is identical; in the Russian version, the chromium content is even slightly higher. Some sources claim that D2 is many times superior to X12MF in terms of quality characteristics and cutting edge sharpness, but experts say that this is a purely subjective opinion of the “like/dislike” type.

Another foreign analogue is Japanese-made SCD11 steel. It is used for the manufacture of knives that have to be used in conditions of increased wear.

The Japanese analogue X12MF is different:

• strength;
• high level of impact strength;
• excellent cut;
• high carbon content;
• maintaining sharpness even after extreme cuts using power cutting.

Of the Russian steel grades, Kh6VF, Kh12VM, Kh12F1 are considered analogues. But they are more likely to be substitutes with lower characteristics of metal hardness and sharpness. But steel of these grades is resistant to corrosion, which is why knife manufacturers often prefer them.

Quenching and tempering of hypereutectoid and ledeburite steel for die tools

The properties and behavior during heat treatment of hypereutectoid and high-chromium steel were discussed earlier, and the hardening regime was indicated in Table.
33. Therefore, only the main features and differences in the heat treatment of tools for cold deformation of metal are given here.

A tool for this purpose is often larger in size than a cutting tool. In such cases, steel hardening temperatures (except for X12M and X12 steel) should be assigned according to the upper limit specified in Table. 33, and when hardening a larger tool - 10-20° above this upper limit.

In carbon steel dies it is often necessary to ensure the deepest possible hardenability. The latter increases if the steel has a thin-plate pearlite structure before hardening. This structure is created in steel as a result of normalization. Therefore, it is sometimes advisable to normalize large carbon steel dies before hardening.

The hardenability of carbon steel also increases if its heating temperature increases during quenching, as shown in the diagram in Fig. 83. Carbon steel grades containing a higher percentage of manganese have higher hardenability: U8G and U10G (Fig. 84). However, these grades of steel can only be used for the manufacture of dies of simple shape, since the higher manganese content in high-carbon steel increases its tendency to crack during hardening V.Ya. Dubovoy recommends using the following processing mode for large dies made of carbon steel U8-U10 (Table 41).

According to V.Ya. Dubovoy, the durability of large dies that received higher heating during quenching or underwent preliminary normalization increases approximately twice as compared to the durability of dies that were heated during quenching according to the usual regime established for carbon steel.

Die tools made from steel X12M, X12 and 7X3 must, as a result of heat treatment, be given high wear resistance with sufficient viscosity. Therefore, when hardening this steel, it is not necessary to transfer a large amount of carbides into solid solution. In addition, the deformation of a complex tool made from X12 and X12M steel during the hardening process should be minimal. For these reasons, there is no need to heat this steel to the high temperatures indicated in table. 33 and assigned to cutting tools. The heating of the die tool is used as follows:

Cooling of dies made of steel X12M, Xl2 and 7X3 can be done in oil or in a stream of air, after which the steel receives a hardness in the range of 62-65 Rc and a martensite structure with a significant amount of carbides that have not passed into solution (as well as 10-20% retained austenite) . Cooling high-chromium steel in a stream of air creates slightly lower residual stresses than cooling in oil. Therefore, to reduce the deformations that occur during hardening, dies made of X12M and X12 steel are cooled in air. However, dies of complex shapes, especially those with sharp transitions, are more rationally cooled in molten salts or in a special oven at a temperature of 450-475° and after holding for 10-20 minutes. transfer to air.

Steel X12M and X12, heated during hardening to 975-1050°, retains high hardness (60-62 Rc) after tempering at 425-475°; a further increase in the tempering temperature causes a decrease in hardness. Since these grades of steel are used to make dies that operate mainly under conditions of increased wear, the tempering temperatures of X12M and X12 steel are usually set within the limits specified here. Tempering is carried out once with a holding period of 2-5 hours depending on the size of the stamp. High-precision dies, in which it is necessary to maintain the size that was before hardening, are tempered 2-3 times at 509-520°, since additional tempering, promoting the complete decomposition of retained austenite, increases the size of the die. The hardness after such tempering is 55-60 Rс.

The tempering temperatures of stamping tools made from steel grades X, ШХ15, ХГ, Х09, 9ХС, У8-У12 are set within the limits specified earlier if the tool operates under conditions of increased wear.

If the dies experience impacts during operation and must have a higher viscosity, then their hardness after tempering should be below 60 Rc. In this case, we can proceed from the following data: for stamps of a simple shape, take a hardness of 57-60 Rc, and for stamps with sharp transitions - 55-57 Rc; for dies processing softer metal, for example, non-ferrous metals, 48-55 Rc. In this case, higher tempering temperatures are set for the stamping tool (Table 42).

Some types of tools, for example, punching stamps, punches, etc., have a long fastening part that works in bending, which requires a more complex heat treatment regime in order to maintain high hardness in the working part and obtain lower hardness with increased viscosity in the fastening part. parts. To create heterogeneous hardness along the length of the tool, you can use either different hardening modes for the working and fastening parts or a differentiated tempering mode. In the first case, the tool is heated in a lead or salt bath with only the working part, or it is heated completely in a furnace, but only its working part is immersed in oil.

However, to obtain a smooth transition in hardness and mechanical properties, it is more advisable to create uniform hardness and structure in such dies after hardening, and then temper the die by heating it to different temperatures. For this purpose, such tools, made, for example, from steel X, X09, XBP, U10, U12, etc., after hardening, are first tempered completely in an oil bath at 180-200 ° to relieve stress, then they are transferred to a salt bath at a temperature 300-350° for releasing the transition part. The instrument is immersed vertically in this bath so that its working part protrudes approximately 10-12 mm above the bath mirror; The exposure time should not exceed 10-25 minutes. depending on the size of the tool to avoid heating its working part. The hardness of the transition part after tempering is 45-55Rс. Then the fastening part is tempered by immersing it for 20-30 minutes. in a salt bath with a temperature of 420-450°; the hardness of the fastening part after tempering is 40-45 Rс. After this, the final tempering of the working part is carried out to the required hardness by immersing the entire punch in an oil bath at a temperature of 210-250° for 1-2 hours.

This method cannot be effectively used for long and thin punches, since they can cause significant movement and deformation during hardening. Therefore, punches of this type are heated during hardening only in the working part.

Areas of application for x12MF steel

The characteristics of x12MF allow us to classify this steel as stamped tool steel. And the entire set of useful properties of this brand determines the main direction of its application - the engineering industry, and to be more precise, heavy engineering. Steel x12MF is used as a starting material for the production of:

• drawing boards;
• portages;
• peepholes for calibrating bar metal for thread rolling;
• bending and forming dies;
• complex sections of body dies (during hardening they should not be subject to significant volumetric changes and warping).

Also, stampings of active parts of electrical machines and electromagnetic systems of electrical devices are made from steel x 12MF. Currently, the use of this steel for domestic purposes, in particular, for the production of hunting knives, is becoming increasingly important.

Use of steel x 12MF for making knives

Perhaps this is why more and more men are choosing knives made of x12MF steel. Then it will be interesting to know what unique characteristics such steel has and why it is better than similar materials?

The main characteristics of x12MF include a set of qualities that are given by the chemical elements present in steel. Without exaggeration, this is a unique alloy containing only 14.5-16.5% carbon.

Carbon makes steel hard, and its amount affects the wear resistance, and therefore the safety of the cutting part of the knife. The higher this indicator, the longer the period you can use the knife without sharpening. Of course, there are always two sides to a coin, and increased carbon content in steel can lead to corrosion.

x12MF steel contains chromium

And that is not all. During the production and calcination of steel, molybdenum is added to it. It is used as an alloying additive in the steelmaking process, which increases abrasion resistance and enhances the interaction of elements with chromium, which increases the hardenability of steel and makes the alloy more uniform.

What benefits do x12MF get from this feature? A blank of steel, which in the hands of a blacksmith has turned into a knife from the tip of the blade to the handle, will allow you to have homogeneous steel, identical in every millimeter

It is very important. After all, the strength of a chain is in its weakest link.

In this case it is not there. Steel x12MF is almost uniform in every millimeter of the blade cut.

This brand also contains vanadium. It is added to all high speed and tool steels because vanadium improves their hardness and strength. Thanks to its use, knives become much more durable.

compensates for the effects of carbon in terms of corrosion

But the most interesting part comes from how steel works in practice. Numerous experiments carried out on knives made from the x12MF brand showed the following results.

During the experiments:

• made more than 300 cuts of synthetic rope with a diameter of 2 cm;
• we tested the strength of the cutting part by making 100 cuts on an oak block;
• opened cans;
• planed wooden branches;
• they hit a metal rod with a blade, and also tested the steel by chopping the spines and bones of a wild boar.

The steel handled all the tests perfectly. As one would expect, no serrations appeared on the blade of the knife. The most amazing thing happened later, when the knife cut the newspaper under its own weight! Without any tears or tears in the paper. This is such a miracle steel. And this after 300 cuts of rope, hitting a wooden and metal block with a dozen open tin cans!

Application area

In industrial production, steel is widely used in the manufacture of cold forming tools:

• bending and forming dies;
• body die sections;
• perforated, cutting dies and punches;
• drawing boards and dies;
• calibration, profiling rollers of complex shape;
• rolling dies.

Blade manufacturers often prefer this steel in the manufacture of folding, tactical, hunting and camping knives. For example, the Leatherneck Marine tactical knife from Cold Steel. The famous American master Bob Dozier prefers to work with X12MF all his life. It is precisely this that distinguishes it from a number of other brands for its unique properties. His knives made of this steel will decorate any collection.

In Russia, knife production is carried out mainly in small designer workshops. The main products are hunting knives and survival knives. Serial production of knives has been established in Vorsma, Zlatoust, and Kizlyar. In these cities, the use of X12MF steel is justified by the presence of a good material and technical base and traditions. You should only order blades from manufacturers with a good reputation.

For kitchen

For fishing

For hunting

For a scout

knives made of steel Х12МФ (D2/SKD11)

In the photo: Finnish blade “Vacha” by master Dmitry Zainullin, made with a blade made of X12MF steel.

Initially, steel was intended for the manufacture of cold-formed tools (saws, woodworking knives, cutters, cutters...).

The steel contains 1.4-1.6% carbon and 11-13% chromium, which makes it quite resistant to humid environments, and the amount of iron carbides and proper heat treatment allow this steel to be hardened to 61-63 HRC. Foreign analogues of steel are designated D2 (American) and SKD11 (Japanese). And one of the most famous knife manufacturers, Bob Dozier (USA), worked almost exclusively with this grade of steel, achieving amazing results in its heat treatment.

Characteristics of steel X12MF

If you have already visited various knife sites, then you are very familiar with such a characteristic as HRC, if not, then I will give a short explanation. HRC is the hardness on the Rockwell scale, the higher it is, the stronger the steel, and the knife holds an edge longer, this characteristic fluctuates maybe from a little over 40 for a Chinese stamping to 65-70 for a Japanese samurai katana.

For knives made of X12MF steel, HRC varies from 61 to 64 units. Our products are manufactured with HRC 62. Considering the composition described above and the chemical elements used, X12MF is very easy to process and has good hardenability and wear resistance. Foreign analogs of X12MF: D2, K110, Z160

, Chinese
Cr12MoV
.

When and how did damask knives originate?

During his campaign in India, Alexandra the Great especially noted the quality of the knives and combat sabers of the Indian noble warriors. Their blades easily cut through not only armor, but also weapons, and the sharp blades of their knives ripped through chain mail like butter. These were the first mentions of damask knives by Indian craftsmen. The unusual metal of Indian foundries was famous not only for its hardness, but also for its flexibility. Some craftsmen, using copper sulfate, which was added to the steel during processing, obtained white, green and blue blades.

Do not confuse damask steel with Damascus steel; these are completely different metal casting technologies. Damascus steel is more flexible than damask steel, although it is as strong as damask steel. Those who think that the appearance of blades differs from ordinary ones in that they have patterns depicted on them are mistaken. Damask steel casting technology makes it impossible to depict designs on the blade. The main difference between the two types of rare steels can only be determined in practice by an experienced craftsman or an experienced hunter.

As for the appearance of damask steel in Rus', it must be said that foundry as a craft existed in our country back in the 9th-10th centuries. Steel in Rus' was famous for its strength; not only weapons, but also household items were made from it. During the development of industry (XVII-XIX centuries), steelmaking in Russia, namely in Tula, Nizhny Tagil, Verkh-Isetsk, Zlatoust and other centers, made a powerful leap forward. It was at the Zlatoust plant that metallurgist P. Anosov, after much experimentation, found a method for producing damask steel. For many centuries before him, foundry masters tried in vain to learn the secret of making a blade that could easily cut through any steel and not become dull. After the discovery of Peter Anosov, it turned out that damask steel is just ordinary carbon iron, which, after a special method of crystallization, cooling and a certain set of materials, acquired unique qualities.

Types of damask knives

Damask knives, like others, are divided into two categories: with an open (fixed) blade and folding. Damask steel ones are popular not only among knife lovers; they are used by:

• Hunters and fishermen. Hunting knife made of damask steel is one of the most popular categories. They are used not only by professional hunters and fishermen, but also by the military;
• Tourists (especially the category of extreme tourists who like to spend time in the mountains or taiga). In their arsenal you can find not only damask knives with a fixed blade, but also folding ones;
• Simple housewives and professional chefs. Although there are no special kitchen knives made of damask steel, nevertheless, such models cope much better not only with slicing vegetables, but also with cutting meat and fish;
• Collectors and simply weapon lovers.

The latter prefer beautifully decorated handmade damask steel knives, but hunters and professional chefs value them for their high quality of cutting.

X12MF steel for knives: pros and cons

The advantages of X12MF steel include:

• Production is cheap - the composition includes readily available components at low cost, and the metal is often made from recycled materials. As a result, the low cost of knives with a blade made of X12MF steel.
• The performance characteristics of the knife are completely predictable. If you follow all the rules for caring for metal and its use, then even constant exposure to a wide range of temperatures will not reduce its properties.
• The sharpness of the knives is perfect. Optimal sharpening angles coupled with high metal hardness (HRC 63-64 units) provide the edge with high wear resistance. The sharpness of the blade is maintained for a long time even with active use of the tool.
• Maintenance of cutting tools made of X12MF steel is minimal. The fact is that metal practically does not rust, so there is no need to constantly polish it, coat it with any specific coating or constantly soak it with anti-corrosion liquids.

If we talk about the disadvantages, then you should pay attention to the following:

• It is almost impossible to carry out any technological operations with steel related to heat treatment at home. During forging, the metal workpiece cracks, and if heating to the required forging temperature does not occur, the steel will simply crumble.
• To sharpen the cutting edge of the blade, you will need special equipment.
• Bending loads can only be minimal. Therefore, knives with a blade limited in length are made from the steel grade in question.
• With frequent contact of metal with salts and acids, so-called pitting corrosion begins to appear.
• A blade made of X12MF steel will never shine - it will not be possible to polish it. The knife will always look dull.
• In the field, even straightening a knife can become a problem, because the metal is very hard and for this you will need a special tool such as a diamond-coated grinder.

Production nuances

Industrial production of X12MF steel is established using a proven technical process. Depending on the delivery conditions and customer requirements, the melt is poured into molds or finished molds, taking into account allowances for machining. A small degree of shrinkage allows you to assign minimal allowances.

During cooling and crystallization, the formation of a dendritic structure is inevitable. In this case, the precipitation of carbides occurs unevenly across the cross section of the casting. To eliminate structural heterogeneity, annealing is performed.

Of interest is the production of castings using the electroslag remelting (ESR) method. Its use makes it possible to obtain an isotropic structure in all directions of casting. Metal produced by the ESR method has better forging characteristics. Similar results are obtained using the vacuum arc remelting (VAR) method.

During forging, the structure of the metal is further improved: heterogeneity in composition is eliminated, the dendritic structure is broken up, grains are refined, and voids in the crystal lattice are filled.

The performance properties of blades are significantly influenced not only by the chemical composition, but also by the smelting method. Preference is given to workpieces obtained by ESR, VDP and powder methods.

Knives made of steel X12MF

Kitchen knives made of X12MF steel are rarely made; more often you can find hunting tools on sale. The brand in question is often used for the manufacture of Yakut knives.

"Bakhycha"

This is a small knife with the following characteristics:

• the blade is wide;
• handle 115 mm;
• blade 110x36x4 mm;
• handle material – walnut;
• the shape of the descent on the blade is straight;
• type of sharpening - one-sided.

Cutting knife made of X12MF steel.
The handle has duralumin elements that serve both as decoration and as a device for striking. The tool is lightweight and fits comfortably in your hand. The “Bakhycha” knife is especially often used for skinning animals and for cutting meat and fish.

"Cervical"

Such a knife is considered universal because it can be used to perform various business operations - cutting, making holes in non-solid material, cutting meat/fish.

Product quality characteristics:

• handle length – 110 mm;
• blade parameters – 110x22x4 mm;
• the handle is made of Karelian birch (stabilized);
• The bolster is made of cupronickel;
• the descent on the blade is straight;
• sharpening is one-sided.

"Neck" knife made of steel X12MF

The name "neck" knife was given by the type of wear - a sheath and a loop made of genuine leather allow it to be worn around the neck.

"Hotonoh"

This Yakut knife has a narrow blade 179 mm long, it also has a second name - “tundra”. The blade is made of steel X12MF, the handle is made of Karelian birch. The sharpening is standard one-sided, the descent on the blade is straight. The cutting tool is used in hunting; it is excellent for deboning meat and cutting fish.

The Khotonokh knife is sold together with a sheath made of genuine leather; before sale, it undergoes a test protocol and has a quality certificate. The manufacturer guarantees its product for 12 months of proper use.

"Bychakh"

This is a Yakut tundra knife with a narrow blade and belongs to the category of universal cutting tools. Product characteristics:

• steel hardness – 62 HRC;
• metal – forged, alloy grade X12MF;
• handle length – 135 mm;
• blade parameters – 150x25x4 mm;
• handle material – birch bark and wenge;
• Pritin is made of duralumin;
• sharpening of the cutting edge is one-sided;
• The descent on the blade is straight.

Yakut tundra knife made of steel X12MF

Such a long blade is convenient for cutting animal carcasses and fish; it can also cut soft materials and even make holes.

Rules for using knives made from this material

The main reason for knife failure is the blade breaking. This happens due to the application of bending forces. Steel is very sensitive to loads other than axial ones. Another common problem is loss of aesthetics. This happens when the knife is not properly cared for. To prevent this from happening, you must follow simple precautions:

1. The knife must not be thrown, thrown, dropped, or used as a lever. It is also not recommended to chop bones when cutting carcasses to avoid chips on the cutting edge.
2. It is important to avoid exposing the fabric to an acid-base environment. Pitting corrosion develops very quickly and can ruin the appearance of the product.
3. The ideal sharpening angle is 35 degrees. This value must be adhered to when restoring the cutting edge.

Ignoring these rules is guaranteed to lead to breakage of the knife. The properties and characteristics of a knife made of X12MF steel will help you maintain simple rules for storing the product:

1. It is best to store a knife in a sheath. This method will protect you from accidental falls and related chips.
2. After use, it is better to rinse the knife with running water, wipe it dry with a paper napkin, and lubricate it with petroleum jelly or ballistol.
3. Once every four months it is necessary to polish the blade with GOI paste and edit it on a leather belt. If necessary, use fine-grained diamonds. High-quality polishing reduces the risk of pitting corrosion.
4. The wooden handle of a knife should be regularly treated with an antiseptic. This procedure protects against mold and bacteria. Caring for a metal handle should be the same as caring for a blade.
5. If a corrosion spot is found on the canvas, this place must be lubricated with ballistol. After some time, the stain should come off.

Only recommended gun oils should be used. The use of poor quality oils will lead to a decrease in the quality and technical characteristics of a knife made of X12MF steel.

On a hunt, fishing, picnic, on a camping trip, or in the process of professional activities, a knife made of X12MF steel will become a friend and faithful assistant. With proper care and careful handling, it will retain its properties for a long time and will delight you with its appearance.

It is better to store knives in sheaths

The knife should be rinsed immediately with running water.

It is necessary to polish the steel on time

Treat the handle with antiseptics

Disadvantages of U10A alloy

The knife, cast from U10A steel and hardened to 52 hrc, has gained fame as the sharpest; the blade retains its sharpness for a long time, but is afraid of blows. The high hardness of the material makes it difficult to sharpen blades in the field. An excellent solution to the problem would be a combination of U10A alloy in a package with 7ХНМ tool steel. This composite manufacturing technology has been mastered by ZZOSS. The final product has qualities typical of Damascus knives. The only drawback of the U10A-7KhNM alloy is its susceptibility to corrosion. Timely care will prolong the useful properties of the knife.

Steel X12MF: characteristics

X12MF steel for knives: composition and characteristics

X12MF steel is created by cold deformation using chromium isomers and inclusions of various elements. The composition includes tungsten, manganese, silicon, as well as vanadium, which on average accounts for up to 0.2% of the total mass. The combination of elements has high strength, which is due to the level of hardenability and hardenability of the alloy.

These features provide phenomenal wear resistance of the steel sheet.

Figure 1. Chrome, Kh12MF steel blank and forged knife from a similar blank

The element underlying the alloying of X12MF is chromium (Figure 1), which makes it possible to use cold deformation. It is used to increase cutting performance, as well as direct resistance to all mechanical damage. In turn, due to this, strength increases, as well as hardenability, which is important for creating dimensional matrices. If the chromium content is in the range of 2.5%, then the strength increases above standard values. Warping during hardening smooths out the manganese admixture. When the chromium content exceeds 12%, then significant disadvantages appear during hardening. They are due to the fact that the carbide heterogeneity of the alloy, together with a significant tendency to destroy the carbides themselves, leads to a loss of strength and a decrease in service life. Therefore, when creating the X12MF, manufacturers try not to exceed the 12% mark.

Figure 2. Elements used to make steel: tungsten (1), vanadium (2), molybdenum (3), manganese (4), silicon (5)

If we consider the entire list of elements applicable for production, we get (Figure 2):

• Tungsten reinforcement element. Increases durability, ensures wear resistance, hardness of products, and significantly increases cutting properties when sharpening;
• Hardening vanadium. Hardening of Kh12MF steel is carried out with the participation of vanadium, which has a high density. This element and its carbide directly reduce the compliance of die steels with respect to overheating and greatly increases the resistance of Kh12MF to hardenability. Just tenths of an element affect the compliance, ductility, and strength of steel sheets;
• Hardenability-improving molybdenum. Ultimately, viscosity increases due to strengthening of bonds between elements. The negative aspect of including molybdenum in the composition is that molybdenum has a detrimental effect on scale resistance. Its content in this alloy ranges from up to 2% of the total mass maximum;
• Stabilizing balance of warpage and overheating level manganese;
• Silicon necessary to maintain the hardenability process. This element serves as the basis for increasing durability.

Figure 3. Folding knives made of steel X12MF

Folding knives made of X12MF steel (Figure 3) are reliable tools for use in various fields (of course, for legal purposes). They are suitable for both outdoor activities and for use at home and in the kitchen. Users actively choose X12MF steel, the properties of which can satisfy all the wishes for a knife. What is the reason for this? High resistance to corrosion, long service life, cutting efficiency are solid competitors to other alloys that form the basis of knives. After all, not all types of steel currently manufactured are hardened at 950 degrees Celsius, which means they acquire a hardness of about 65 HRC units. However, the forging process is quite difficult. Initially, this type was used in production, electrical engineering, and various mechanized devices. But recently there has been a strong trend towards making knives from this steel. The end consumer especially liked hunting models, which are somewhat different from the second most popular - tourist models (Figure 4).

Figure 4. Hunting (left) and tourist (right) knives made of X12MF steel

Selecting the correct temperature, as well as parameters according to the technology map, requires sensitive attention from the manufacturer. Even taking into account all the complexities of the production process, there are still craftsmen who make knives and blades from this steel in industrial and non-industrial conditions. How applicable is X12MF steel for knives? We will consider the pros and cons of products made from this material further.

Application

It is best to understand the area of ​​use if you compare X12F1 with 12X steel. It is characterized by increased viscosity, which in some cases is very valuable. On the basis of such metal it is possible to make cold stamps that wear out little (were slightly abraded). Basically, in such industrial stamps the working segment has a rounded shape.

These devices are made with the expectation that they will not experience shocks and strong impacts.

It is also possible to receive:

• boards for drawing manipulations;
• calibrating eye elements for processing metal rods (with subsequent thread rolling);
• dies for technical bending;
• stamping equipment for molding;
• complex sections of the body stamp.

All such tools are hardened using a special technology. Heat treatment should exclude significant volumetric changes and warping. Dies and punches for some types of dies can also be made on the basis of Kh12F1. This alloy is also used to make stampings in the active zones of electrical machines. The product described is also suitable for producing:

• advanced hole-punching matrix systems that form sheets well;
• profiling roller units of complex geometry;
• gears that are standards;
• drag;
• reeling lane;
• punch parts and matrix blocks that extrude metal that is not subject to heating at pressures up to 1400-1800 MPa.

ESSENCE OF THE STEEL PRODUCTION PROCESS

Die tool steel is difficult to machine. It is necessary to strictly follow the quenching and tempering technology in order to obtain a high-quality alloy.

The metal is smelted in electric furnaces, open-hearth furnaces and oxygen converters, strictly maintaining temperatures up to 950 0C. If the temperature regime is violated, the steel will become brittle when cooled and will crumble during forging. Forging temperature 850 – 1140 0C.

The crystal lattice becomes stable after quenching and annealing. Hot metal releases internal tension and becomes solid.

X12MF steel is hardened and tempered several times to make it as strong as possible. The steel sheet is then hammered to give the alloy stability. The endurance of steel is 650 – 800 MPa.

The sheets are fired in a vacuum furnace and sent to metallurgical plants in the form of rolled products, wheels, ground and calibrated rods, strips, sheets and plates, blanks, slabs, forgings and forged blanks.

X12MF steel is cast exclusively in production foundries.

Steel X12MF characteristics and application

The technical characteristics of X12MF steel have precisely those complex properties that determine its uniqueness. One of those steel grades that are popular not only at enterprises, but also among craftsmen.

The use of X12MF steel cannot be called universal: the limits of its use are limited.

A set of alloying elements determines its structure and determines its narrowly targeted purpose: it is a tool die steel. High manufacturability - machinability by cutting and pressure makes it possible to produce:

• stamps of complex shapes for dies: hole-punching;
• perforated;
• bodywork;

But steel grade X12MF has gained great popularity due to the fact that it is used for the manufacture of knives.

And the point is not even that the blade turns out to be very durable and does not need to be edited for a long time.

Corrosion resistance, good machinability by cutting and forging - these are the characteristics that position the X12MF brand as one of the best in this segment.

But the use of knives made from this grade of steel is characterized by high fragility: they cannot be bent or thrown into wood.

Advantages of the alloy

The physical and chemical properties of 50x14mm steel give the knives made from it excellent qualities. She has:

• Corrosion resistance, especially to chlorine-containing environments. The alloy acquires this property due to the presence of alloying elements: chromium, molybdenum and silicon. The addition of chromium leads to the formation of an oxide film on the surface of the metal, which protects it from rust. Steel containing more than 13% chromium is called “stainless,” which indicates its resistance to corrosion. Molybdenum and silicon enhance the effect of chromium in the alloy, making its composition more uniform.
• Resistant to weak alkalis and some acids. The metal acquires this quality due to the admixture of molybdenum. It makes steel resistant to aggressive environments.
• Good resistance to impact loads, which the alloy acquires due to the presence of molybdenum, which reduces the fragility and fragility of the blade.
• Sufficient hardness, which allows you to sharpen knives yourself and use them for a long time without sharpening. Steel acquires this property due to the admixture of manganese, which gives the metal a grainy structure. This helps to increase the strength of the blade, its rigidity and wear resistance. Manganese and silicon impurities also improve the strength and rigidity of steel.
• The ability to easily (without deterioration of properties) tolerate elevated temperatures. Molybdenum helps to increase heat resistance.
• Despite all the above characteristics, steel grade. 50x14mf has an affordable price, which can also be considered an advantage.

X12MF

X12MF Order >>

General information about the material X12MF

Mechanical properties of X12MF

Mechanical properties depending on test temperature

Temperature of critical points X12MF

Physical properties of X12MF

st.st.45HN2MFA 85x85 square 5tn

st.48ХН3МА 200х200 square 45tn

st.5ХНМ square 125; 130; 160; 180;

st.35ХМ f860-f1250 forgings 20tn

st.40Х f610-f1240 forgings 20tn

st.40ХН f450-f1230 forgings 30tn

• ROLLED METAL Rolled metal 12ХН3А, 12Х2Н4А, 20ХН3А, 18Х2Н4МА, 20ХГНР, 30ХГСН2А, ОХН1М, 40ХН2МА, 30ХМА, 15ХМ, 15Х5М, 12Х1МФ, 12Х2MVFA, 25Х1МФ, 2 5Х2М1Ф, 38Х2МУА
• Advantages Shipment volumes: from 1 piece to a complete set of cars and wagons. Flexible pricing policy. Minimum markup, maximum turnover, deferred payment.
• Supply of steel grades Supply of rolled steel of various grades of steel: 15xm, 15x5m, 12x1mf, 25x1mf, 38x2mua, 25x13n2mf, 30x2GSMF, 30xgsa, 65g, 25xgt, shx15 and other steel grades.
• Contacts Sales Manager Director Needs “InMet” will buy rolled metal. Current needs are published in this section. Tel. purchasing department: (351)723-06-81

Steel X12MF tool stamping

Decoding

• According to GOST 5950-2000, the absence of numbers before the letter designation indicates that the mass fraction of carbon in steel is approximately 1%.
• The letter X in the designation of steel indicates that the steel is alloyed with chromium. The number 12 behind the letter means that the mass fraction of the chromium alloying element is approximately 12%.
• The letter M in the designation of steel indicates that the steel is alloyed with molybdenum. The absence of numbers behind the letter means that the mass fraction of this alloying element is approximately 1%.
• The letter F in the designation of steel indicates that the steel is alloyed with vanadium. The absence of numbers behind the letter means that the mass fraction of this alloying element is approximately 1%.

Substitute

steel Kh6VF, Kh12F1, Kh12VM.

Foreign analogues [1, 2]

Type of delivery

• Long products, including shaped steel: GOST 5950-73, GOST 2590-88, GOST 2591-88.
• Calibrated rod GOST 5950-73, GOST 7417-75, GOST 8559-75, GOST 8560-78.
• Polished rod and silver steel GOST 5950-73, GOST 14955-77.
• Strip GOST 4405-75.
• Forgings and forged blanks GOST 5950-73, GOST 1133-71.

Characteristics and application [3]

X12MF steel is a high-alloy (high-chromium) semi-heat-resistant tool steel of high hardness with increased wear resistance. This steel is widely used for the manufacture of cold dies and other tools that deform metal in a cold or relatively low-heated state. Most high chromium stamped steels contain an average of 12% chromium (Cr) and a high percentage of carbon. This leads to the formation of a large amount of chromium carbides (Cr7C3).

It is the large amount of carbide phase (under all heat treatment modes) that makes the steel highly wear-resistant.

Kh12MF steel also has good ductility and grindability [1].

The required high hardness of steel type X12 can be obtained by hardening

it from high temperatures (1150 °C) in oil and consequently obtaining a large amount of retained austenite, and then by cold treatment and tempering

achieve decomposition of retained austenite and obtain high hardness (>60 HRC).

But more often, steel type X12 is hardened at temperatures that give the greatest hardness

after hardening (from 1050-1075 °C) and subsequent low tempering (at 150-180 °C).

The hardness in both cases is the same (61-63 HRC), but in the first case the steel

has a higher red resistance, and in the second - greater strength.

The hardness of Kh12MF steel reaches its maximum value (61-63 HRC) after hardening from 980-1020 °C; the steel retains a grain grade of 10 and 15-20% austenite (which is more than many non-heat-resistant steels) [1].

With an even greater increase in the quenching temperature, the hardness decreases from 50-55 HRC and lower due to a sharp increase in the amount of austenite. With an increase in heating temperature >1000-1020 °C, the strength also decreases due to grain growth and the influence of austenite [1].

The elastic limit of steel Kh12MF (for hardness 56-57 HRC) is ~1300 MPa.

Kh12MF steel deforms little during hardening, and when thermal finishing is used, deformation can be reduced to almost zero. Therefore, this steel should be recommended for tools of complex shape, for which deformation during hardening is unacceptable.

The viscosity of Kh12MF steel after quenching to fine grains (from 1025 °C) and tempering at 200 °C (58-60 HRC) in the longitudinal direction is 0.28-0.3 MJ/m2 for rolled products with a diameter of 16 mm and 0.26 and 0.16 MJ/m2 for rolled products with a diameter of 40 and 125 mm, respectively. In the transverse direction it is even lower: 0.11 and 0.07 MJ/m2 for rolled products with a diameter of 40 and 90 mm [1].

Molybdenum and vanadium in X12MF steel are necessary additives; they help maintain fine grains and increase strength and toughness [1].

Approximate purpose of tool alloy steel X12MF (GOST 5950-2000)

• For cold dies with high resistance to abrasion (mainly with a rounded working part), not subject to strong impacts and shocks;
• for drawing boards and dies;
• eyes for calibrating bar metal for thread rolling;
• bending and forming dies;
• complex sections of body dies, which during hardening should not be subject to significant volumetric changes and warping;
• dies and punches for cutting and perforating dies;
• stamping of the active part of electrical machines and electromagnetic systems of electrical devices;
• for profiling rollers of complex shapes;
• complex hole-punching matrices when forming sheet metal;
• reference gears;
• rolling dies;
• portages;
• matrices and punches of cutting, perforating dies (including combined and sequential) with a complex configuration of working parts.

Temperature of critical points, °C [4]

Chemical composition, % (GOST 5950-2000)

Temperature of hardening of steel Х12МФ [1]

*1050-1070 °C for increased heat resistance and retention of hardness during heavy grinding and 1020-1040 °C for minimal deformation.

Heat treatment modes of steel Kh12MF [4]

NOTE.

1. I - normal mode;
2. II - used if treatment according to mode I does not provide the required viscosity:
3. III - for cutting tools when wear resistance is required;
4. IV - used when size constancy is required.

Final heat treatment modes [4]

Cold treatment [1]

This treatment with cooling to -70 °C increases hardness by 1-3 HRC and resistance to plastic deformation, but reduces viscosity. The increase in wear resistance is insignificant. Cold treatment is used relatively rarely to increase the endurance limit, but subject to a long tempering, which largely relieves the additional stress created.

Structural component of Kh12MF steel having a hardness of 62-64 HRC (rolled ingots 500-750 kg) [1]

NOTE:

1. *1The main structure is martensite;
2. *2Hardening for fine grain (point 10);
3. *3Holiday 160 °C, 1 hour;
4. *4At a distance close to 0.5 radius;
5. K - carbides;
6. Ao—residual austenite.

Hardness as delivered of metal products intended for cold machining (GOST 5950-2000)

Hardness of metal product samples after hardening and hardening and tempering

NOTE. Deviations from the tempering temperatures indicated in the table should not exceed ±10 °C.

Hardness of steel after heat treatment (GOST 5950-73) [4]

Relative wear resistance of steel Kh12MF depending on the amount and type of carbides [1]

NOTE. Test according to Savin-Skoda with a load of 150N.

Impact strength and hardness of steel depending on tempering temperature [4]

NOTE. Hardening from 1000-1030 °C in oil; tempering holding time 1.5 hours.

Mechanical properties depending on test temperature [5]

NOTE. Specimens with a diameter of 10 mm, a length of 50 mm, forged and annealed. Deformation speed 1.1 mm/min; strain rate 0.0004 1/s.

Endurance limit at n = 107 [6]

Technological properties

• Forging temperature, °C: beginning 1140, end 850. Cooling in wells or thermostats [7].
• Weldability - not applicable to welded structures [5].
• Cutting machinability - Kv tv spl = 0.8 and Kv6cT = 0.3 in the hot-rolled state at HB 217-228 and av = 710 MPa [5].
• Tendency to temper brittleness - prone [8].

Heat resistance

NOTE. Sandability is satisfactory [5].

Critical diameter, mm, during hardening [5] in various environments

Density ρп kg/cm3 at test temperature, °С

Linear expansion coefficient α*106, K-1

Electrical resistivity ρ nom*m

conclusions

If you primarily need toughness and strength in a knife, the knife is intended to be used for batoning, opening cans, digging around fire pits, etc. and money is short, look towards the good old carbon. It's cheap and cheerful. If your budget allows, look towards CPM3V or PGK powder steels.

If you prefer to kayak or are a fisherman, then naturally look towards stainless steel. Constant dampness in a boat or while fishing will quickly cause the knife to bloom in a lush red color. If you don’t have a lot of money, look towards domestic stainless steel, and if your budget is larger, then it’s better to choose N690.

If you prefer aggressive cutting, and for a long time, then powder steels are your choice. At the moment they are more than available, at least the basic brands. At Hansa, you can easily select a strip of steel of interest and negotiate with the craftsman about heat treatment and production of the entire knife. A designer knife from Elmax or M390 can confidently fit into a budget of 6-8 thousand, and this is a very good choice. Monsters cost closer to 15-18 thousand per knife.

If you like beautiful patterns on the blade, your choice is Damascus and damask steels; their consumer properties are very much inferior to modern tool steels, but they can be beautiful. Just remember that real damask steel costs as much as an airplane wing.

Brief overview of steel 95Х18

This stainless steel is considered one of the best for making knives. This is not my opinion, and not the opinion of Russian knife makers, this is what large manufacturers of Russian knives think. Indeed, there is no point for them to tinker with other types of steel when 95X18 holds an edge well, does not rust and is relatively easy to process. Although in recent years, even large knife companies have to somehow spin around and try new types of steels in order to interest the client.

Despite this, knives made from 95x18 have an excellent price-quality ratio. Blades are hardened to 57-59 HRC, which is quite enough for long-term retention of sharpening, and for relatively easy sharpening. The fact that 95X18 knives do not rust makes them ideal for those users who are not used to caring for knives.

A knife made of 95X18 will forgive even the fact that you put it dirty and wet in the sheath and remember about it the next day. An analogue of steel 95X18 is Japanese steel AUS-8.