高温淬火改善超高强度钢应力腐蚀断裂抗力的研究

IMPROVEMENT ON SUSCEPTIBILITY OF ULTRA-HIGH STRENGTH STEEL TO STRESS CORROSION CRACKING BY HIGH TEMPERATURE QUENCHING

研究了淬火温度对30Cr3SiNiMoV超高强度钢在3.5%NaCl水溶液中的应力腐蚀断裂的影响。淬火温度从870℃升高到1200℃时,应力腐蚀断裂门槛值K_(ISCC)不断升高,均为沿晶断裂。对原奥氏体晶界偏聚、晶粒尺寸等微观因素的分析表明,该钢K_(ISCC)升高的主要原因是原奥氏体晶粒尺寸的增大。

The effect of quenching temperature on the stress corrosion crackingof 30Cr3SiNiMoV ultra-high strength steel in 3.5% NaCl aqueous solution has beenstudied. The threshold K_(Iscc) may continuously increase with the quenching tempera-ture raised from 870 to 1200℃. All of the fractures are intergranular. The ana-lyses of the segregation along prior austenitic grain boundaries, grain size and othermicrostructural factors revealed that the reason of the increase of K_(Iscc) is mainlydue to the coarseness of prior austenitic grains.