38H2N2MA (38XNMA)

Shafts, connecting rods, bolts, and other large, heavy-duty parts.

Shafts, connecting rods, bolts, studs and other large special responsibility heavy duty parts of complex configuration used in an improved condition.

Classification

Country	Section	Category
CIS, Russia, Ukraine	Structural steel	Alloyed structural steel

Chemical composition

Standard	Fe, %	Si, %	Mn, %	Cr, %	Cu, %	Ni, %	P, %	C, %	S, %	Mo, %
GOST 4543-71	94.68–96.45	0.17–0.37	0.25–0.5	1.3–1.7	< 0.3	1.3–1.7	< 0.025	0.33–0.4	< 0.025	0.2–0.3

Information on suppliers

Wish to advertise here?

Physical characteristics

Temperature, °C	$$E\cdot 10^{9}$$, $$MPa$$	$$\alpha\cdot 10^{6}$$, $$K^{-1}$$	$$\varkappa$$, $$\frac{W}{m\cdot K}$$	$$c\cdot 10^{-3}$$, $$\frac{J}{kg\cdot K}$$	$$R\cdot 10^{-6}$$, $$\Omega\cdot m$$
20	213		38		0.322
100	206	11.9	37	0.49	0.398
200	194	12.5	35	0.502	0.482
300	180	13.1	35	0.523	0.592
400	174	13.3	33	0.532	0.74
500	164	13.8	32	0.565	0.91
600	157	14.1	30	0.59	1.09
700	141	14.6	28	0.615	1.3
800	129	11.8	28	0.67

Mechanical properties at 20 °C

Rolling	Standard	Size, mm	Tension	Classifiers	$$\sigma _{U}$$, $$MPa$$	$$\sigma_{P}$$, $$MPa$$	$$\epsilon_L$$, %	$$\psi$$, %	$$KCU\cdot 10^{3}$$, $$\frac{J}{m^2}$$	Treatment
Rod	GOST 4543-71	25			1080	930	12	50	780	Hardening and tempering

Brinell hardness number

Rolling	Standard	Classifiers	Value, HBW
Alloy	GOST 4543-71	annealing	269

Technological Properties

Weldability	Flake Susceptibility	Propensity to temper brittleness
Not applicable for welded structures	sensitive	not inclined

Critical point temperatures

Ac₁, K	Ac₃(Ac_m), K	Ar₃(Arc_m), K	Ar₁, K	Mn, K
753	790	490	370	320

Analogues

USA	Germany
G43499	1.6583 (35CrNiMo6)

Standards

Standard	Description
GOST 4543-71

Description of chemical elements

Element	Units of measurement	Description
Fe	%	Iron
Si	%	Silicon
Mn	%	Manganese
Cr	%	Chrome
Cu	%	Copper
Ni	%	Nickel
P	%	Phosphorus
C	%	Carbon
S	%	Sulfur
Mo	%	Molybdenum

Description of physical characteristics

Parameter	Units of measurement	Description
$$E\cdot 10^{9}$$	$$MPa$$	Elastic modulus
$$\alpha\cdot 10^{6}$$	$$K^{-1}$$	Coefficient of thermal (linear) expansion (range 20°C–T)
$$\varkappa$$	$$\frac{W}{m\cdot K}$$	Coefficient of thermal conductivity (the heat capacity of the material)
$$c\cdot 10^{-3}$$	$$\frac{J}{kg\cdot K}$$	The specific heat of the material (range 20°C–T)
$$R\cdot 10^{-6}$$	$$\Omega\cdot m$$	Electrical resistivity

Description of mechanical properties

Parameter	Units of measurement	Description
$$\sigma _{U}$$	$$MPa$$	Ultimate tensile strength
$$\sigma_{P}$$	$$MPa$$	Proportionality limit
$$\epsilon_L$$	%	Elongation at break (longitudinal)
$$\psi$$	%	Reduction in cross section on fracture
$$KCU\cdot 10^{3}$$	$$\frac{J}{m^2}$$	Impact toughness

Designation of types of weldability

Parameter	Units of measurement	Description
no limits		Welding is performed without heating and without subsequent heat treatment
Boundedly welded		Welding is possible with heating up to 100–120 °C and subsequent heat treatment
Difficult to weld		For obtaining quality welded joints, additional operations are required: heating up to 200–300 °C for welding, heat treatment after welding — annealing
Not applicable for welded structures

Description of temperatures of critical points

Parameter	Units of measurement	Description
Ac₁	K
Ac₃(Ac_m)	K
Ar₃(Arc_m)	K
Ar₁	K
Mn	K