材料期刊网

通过对不同强度等级的40CrNiMo,50Mn 18Cr4MoVN,34CrNi3Mo钢的SCC研究,探讨了强度对不同机理SCC敏感性的影响规律。试验结果表明,强度对不同类型SCC的敏感性有着不同的影响。对于由氢脆和由强化相构成连续活性通道阳极溶解机理控制的SCC,提高强度使钢的抗SCC能力降低;而在塑性变形所控制下的SCC,提高钢的强度可以提高抗SCC的能力。

The susceptibility to SCC (stress corrosion cracking)of steels with different strength levels has been investigated by measuring K_(1scc), hydrogen permeation, acoustic emission and by electronfractography. The metal/environment systems investigated were 4OCrNiMo steel in 3.5% NaCl solution at room temperature, 50Mn18Cr4MoVN steel in 36% Ca(NO_3)_2+3％NH_4NO_3 solution at room temperature and 34CrNi3Mo steel in 30% NaOH solution at 80℃. The test of the last system was conducted at open circuit potential as well as at a controlled potential of-1400mV (SCE). The results reveal that the effect of strength of steels on ehe susceptibility to SCC differs with different mechanism and cannot be gentralizedo When plastic deformation is the controlling factor, the increase of the strength of steels can improve the resistance to SCC.