Steel 40ХН2СМА (EI643M)

Designation

Name	The value
Designation GOST Cyrillic	40ХН2СМА
Designation GOST Latin	40XH2CMA
Transliteration	40HN2SMA
By chemical elements	40CrН2СMo

Name	The value
Designation GOST Cyrillic	ЭИ643М
Designation GOST Latin	EI643M
Transliteration	EhI643M
By chemical elements	-

Description

40ХН2СМА steel is used: for the manufacture of seamless tubes and components for chemical engineering and special equipment.

Note

High-strength steel. The replacement of molybdenum vanadium steel marked 40ХН2СВА (ЭИ643).

Standards

Name	Code	Standards
Classification, nomenclature and General rules	В20	OST 1 90005-91
Norms for calculation and design	В02	PI 1.2.053-78
Blanks. Of the workpiece. Slabs	В31	TU 1-92-156-90
Bars and shapes	В32	TU 14-1-1885-85, TU 14-1-313-72
Steel pipes and fittings to them	В62	TU 14-3-170-73, TU 14-3-674-78, TU 14-3-463-2005

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	Mo	W
TU 14-1-1885-85	0.36-0.42	≤0.011	≤0.015	0.5-0.8	0.8-1.1	0.7-1	2.5-3	Rest	≤0.25	0.3-0.4	-
TU 14-1-313-72	0.36-0.42	≤0.025	≤0.025	0.5-0.8	0.8-1.1	0.7-1	2.5-3	Rest	-	0.3-0.4	≤0.2
TU 14-3-674-78	0.36-0.44	≤0.005	≤0.025	0.25-0.5	0.8-1.1	0.9-1.2	1.8-2.1	Rest	-	0.35-0.45	-

Fe is the basis.
According to TU 14-3-674-78 the chemical composition is given for steel 40ХН2СМА-ВД (ЭИ643М-ВД).
According to TU 14-1-313-72 the chemical composition is given for steel 40ХН2СМА (ЭИ643М). The mass fraction of residual copper in steel should not exceed 0.25%. In bars and forgings, subject to other requirements, deviations from the chemical composition standards for carbon are allowed - + 0.010%, for manganese - ± 0.050%, for chromium ± 0.10%, for nickel ± 0.10%, for tungsten - ± 0.10%, molybdenum - + 0.050%.
According to TU 14-1-1885-85 the chemical composition is given for steel 40ХН2СМА-ВД (ЭИ643М-ВД). To ensure the required grain size, it is allowed to introduce vanadium in the steel smelting at the rate of its content in steel no more than 0.10%, the content of which in steel is not determined. The presence of tungsten to 0.20%, titanium to 0.030% is not a rejection sign. In the steel, partial replacement of molybdenum with tungsten is allowed. The total content of molybdenum and tungsten converted to molybdenum from the calculation: three parts by weight of tungsten replace one part by weight of molybdenum, should correspond to the content of molybdenum indicated in the table. In this case, the content of tungsten in steel should not exceed 0.30%. The permissible deviation in the content of manganese in steel is + 0.010 / -0.020%, in carbon content + 0.010%, in sulfur and phosphorus content, provided that their total content is not more than 0.022%.

Mechanical properties

Section, mm	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Gradation of performance properties of the finished heat-treated parts for OST 1 90005-91
-	1770-1960	-	-	-	-	49.5-52.5
Bars of steel 40ХН2СМА (EI643M) TU 14-1-1885-85. Quenching in oil with 890-910 °C + Vacation at 200-260 °C, air cooling. In the graph KCU KCU values are shown along the fiber/KCU across the grain
	≥1860	≥9	≥40	≥490/106	≤514	-
Long products and forgings on the other 1-92-156-90 (TU 14-1-313-72). Quenching in oil with 890-910 °C + Vacation at 200-260 (200-300) °C, air cooling
	≥1860	≥8	≥35	≥590	≤514	-

Description mechanical marks

Name	Description
σ_U	Limit short-term strength
d₅	Elongation after rupture
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number
HRC	Rockwell hardness (indenter diamond spheroconical)

Technological properties

Name	The value
Macrostructure and pollution	Macrostructure of steel when testing for the breaks in the longitudinal direction and transverse templeto selected from rolled, should not have shrinkage, porosity, bubbles, cracks, delamination, inclusions and placenow and defects of fracture, listed in Annex 3 GOST 10243. The Central porosity, point heterogeneity and phase separation in the square should not exceed 1 points; layer-by-layer crystallization and the bright loop - 3 points reference scales GOST 10243. All other defects under GOST 10243, are not allowed. Pollution steel non-metallic inclusions should be according to the average score is not higher (in points): oxides of point 1,5, 2,0 stroke oxides, silicates fragile 1,0, 1,0 silicates plastic, silicates, non-deformed 2,5, 2,5 sulfides, nitrides stroke and point 1,0.
Features of heat treatment	Bars and forgings on the other 14-1-313-72 put after the heat treatment (low annealing), hardness Brinell hardness no more than 269НВ (indentation diameter not less than 3.7 mm). Recommended low mode annealing: heating to a temperature of 650-680 °C, exposure time 12 hours, air cooling. Forgings to low annealing subjected to preliminary normalization with a temperature of 900 °C.