Heat treatment effect of LPG storage tank
For a certain metal, stress corrosion cracking occurs only in a specific medium environment. (3) In a state of tensile stress. The greater the tensile stress, the shorter the time required for the material to fracture, and the stress required for fracture is lower than the yield strength of the material, generally about 70% of the yield strength. 4.2 Causes of cracks In the parts where the amount of misalignment and edge angle exceed the standard found in the macroscopic inspection, due to the discontinuity of the structure, a large concentrated stress will be generated here. The effect of heat treatment during manufacturing is not good, and the welding residual stress has not been completely eliminated. The actual measured hardness value at the crack is 40 HB higher than that far away from the crack, and the stress corrosion caused by H2S is closely related to the hardness of the steel.
