Description of stainless steels A2 and A4. Characteristics, analogues, application for the manufacture of fasteners

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Mo
GOST 398-96	0.57-0.65	≤0.04	≤0.035	0.6-0.9	—	0.22-0.45	—	Remainder	—	≤0.15	—
GOST 5257-98	0.57-0.67	≤0.04	≤0.035	0.5-0.9	—	0.2-0.45	—	Remainder	—	—	—
GOST 398-2010	0.57-0.67	≤0.02	≤0.03	0.6-0.9	≤0.2	0.22-0.45	≤0.25	Remainder	≤0.3	≤0.15	≤0.08

Fe is the basis. According to GOST 398-96, the allowed content of molybdenum is not more than 0.08%, nickel is not more than 0.25%, chromium is not more than 0.20%, copper is not more than 0.30%. The total content of sulfur and phosphorus should be no more than 0.065%. In finished bandages, maximum deviations in chemical composition are allowed in accordance with the requirements of GOST 380. According to GOST 5257-98, nickel content is allowed no more than 0.30%, chromium no more than 0.25%, copper no more than 0.30%. According to GOST 398-2010, the total proportion of sulfur and phosphorus in steel should not exceed 0.040%. In bandages, maximum deviations of the chemical composition are allowed: for carbon +0.030/-0.020, for manganese +0.050/-0.030, for silicon +0.030/-0.020, for chromium +0.020, for vanadium +0.010%, for phosphorus +0.0050% , for sulfur +0.0050%. The mass fraction of hydrogen in liquid steel should not exceed 0.00020%.

From the history of the creation of the alloy

D2 steel is a relatively new alloy. It was developed a little more than half a century ago in the USA using the electroslag remelting method, which improved the quality of the resulting alloy. With its help, phosphorus and sulfur are removed from the composition, which, according to the developers, are the most harmful. Their increased content often leads to defects and a decrease in the quality of steel.

In America, the alloy was used to make industrial cutting tools and knives.

Later, in Japan, Sweden and Germany, alloys of similar composition were developed, which in their properties are not inferior to the original sample, and in some respects even surpass it. The characteristics of D2 steel and similar ones developed in other countries differ slightly, mainly in the percentage of carbon content.

The Russian analogue of D2 is X12MF steel. The composition of the alloys is similar; differences in properties depend only on the proportions of components used in the alloys and the characteristics of heat treatment.

Currently, the alloy is used for the production of knives and edged weapon blades.

Mechanical characteristics

Section, mm	σB, MPa	d5, %	y, %	kJ/m2, kJ/m2	Brinell hardness, MPa
Bandages according to GOST 398-96, GOST 398-2010. Quenching with separate heating + Tempering
930-1110	≥10	≥14	≥2450	269-321
Bandages according to GOST 5257-98. Quenching with separate heating + Tempering
≥900	≥10	≥14	—	≥250

Advantages and disadvantages

D2 steel used for making knives has its pros and cons. Among the positive properties note:

high level of hardness, allowing you to keep the blade sharp for a long time without sharpening;
the composition of the alloy gives high anti-corrosion properties, although D2 steel for knives is classified as semi-stainless;
excellent resistance to corrosion processes among all carbon steels;
perfectly keeps the edge of a knife or blade sharpened;
a cutting tool made of this alloy can withstand strong impacts and can be used by hunters to chop animal bones or by tourists to cut and process tree branches.

In addition, high-quality products have a low cost, which makes them even more attractive.

Basically, such knives are intended for hunters, fishermen, and tourists who appreciate the advantages of the D2 steel grade, but can be used in everyday life: D2 is used to produce high-quality kitchen knives. Handmade hunting knives, including those made by Kizlyar craftsmen from D2 steel, can be purchased in our online store.

Like any other, the alloy is not ideal, so D2 steel has its disadvantages and drawbacks; there are not many of them.

Although not completely stainless, a knife made from this alloy requires at least minimal care to maintain the best qualities of the product.
It is very difficult to sharpen it in field conditions, without the use of special materials and devices.

In addition, it is worth knowing that the surface of the alloy does not lend itself to final polishing of the blade, so it is almost impossible to find a sparkling, absolutely smooth blade made of D2 steel: its surface will be matte.