40Mn4 Structural Steel Bar

 

40Mn is a high-quality carbon structural steel that can be used in normalized conditions or in quenched and tempered conditions. The cutting performance is good, the plasticity during cold deformation is medium, and the welding performance is poor. Used to manufacture parts subjected to fatigue loads, such as shaft rolls and screws and nuts that work under high stress.

 

The hardenability is slightly higher than that of No. 40 steel. After heat treatment, the strength, hardness and toughness are slightly higher than that of No. 40 steel, the cold deformation plasticity is medium, the machinability is good, the weldability is low, the heat sensitivity and temper brittleness are obtained, and the water quenching is easy to crack. Suitable for fatigue resistant parts, crankshafts, rollers, shafts, connecting rods.

 

Chemical Composition:


Steel TypeStandardCountry CodeC(%)Si(%)Mn(%)P(%)S(%)Cr(%)Ni(%)Cu(%)
S40C(SWRH42B)3828CNS0.37-0.430.15-0.350.6-0.9≦0.03≦0.035≦0.2≦0.2≦0.25
40Mn699GB0.37-0.450.17-0.370.7-1.0≦0.035≦0.035≦0.25≦0.25≦0.25
S40CG4051JIS0.37-0.430.15-0.350.6-0.9≦0.03≦0.035≦0.2≦0.2≦0.25
1039-AISI0.37-0.44 0.7-1.0≦0.04≦0.05   
1040-AISI0.37-0.44 0.6-1.0≦0.04≦0.05   
40Mn417200DIN0.36-0.440.25-0.500.8-1.1≦0.035≦0.035  


Mechanical Properties:


Yield
Rp0.2 (MPa)
Tensile
Rm (MPa)
Impact
KV/Ku (J)
Elongation
A (%)
Reduction in cross section on fracture
Z (%)
As-Heat-Treated ConditionBrinell hardness (HBW)
843 (≥)519 (≥)314241Solution and Aging, Annealing, Ausaging, Q+T,etc133


Physical Properties:


Temperature
(°C)
Modulus of elasticity
(GPa)
Mean coefficient of thermal expansion 10-6/(°C) between 20(°C) andThermal conductivity
(W/m·°C)
Specific thermal capacity
(J/kg·°C)
Specific electrical resistivity
(Ω mm²/m)
Density
(kg/dm³)
Poisson’s coefficient, ν
21--  0.42- 
479694-31.3322 - 
591-1142.2  143124


Equivalent Standard:

 

Brand NameLH No.Mat. No.DINENAISI
VM1007051.115740Mn4-1035

 


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