The 40Mn carbon structural steel plate has good cutting performance, moderate plasticity during cold deformation, and poor welding performance. Used to manufacture parts bearing fatigue load, such as rollers, screws and nuts working under high stress.
The hardenability is slightly higher than 40 steel. After heat treatment, the strength, hardness and toughness are slightly higher than 40 steel, the cold deformation plasticity is medium, the machinability is good, the weldability is low, it has overheating sensitivity and temper brittleness, and water quenching is easy to crack. Suitable for fatigue-resistant parts, crankshafts, rollers, shafts and connecting rods.