30CrMo alloy structural steel executive standard: chromium molybdenum alloy steel, this steel is a kind of alloy steel in China, 30 refers to the carbon content, it is used to manufacture 10.9s, 8.8s high strength bolts. But before use, it must be tested to confirm the content of its ingredients before use. Chinese grade 30CrMo alloy structural steel is equivalent to scm430 in Japan.
30CrMo alloy structural steel has high strength, toughness and high hardenability. The critical quenching diameter in oil is 15-70mm.
30CrMo alloy structural steel also has good thermal strength, which has enough high-temperature strength below 500℃, but decreases significantly at 550℃; when the alloy element is at the lower limit, the welding is quite good, but when it is close to the upper limit, the weldability is medium, and it needs to be preheated to 175℃ before welding.
30CrMo alloy structural steel has good machinability, moderate plasticity during cold deformation, the first temper brittleness in the range of 300 ~ 350℃ during heat treatment, and the tendency to form white spots.
