【摘要】 对GC-4(40CrMnSiMoVA)超高强度钢腐蚀疲劳(CF)裂纹扩展的温度效应进行了研究。结果表明,GC-4钢在3.5%NaCl溶液中平台区(中△K区)CF裂纹扩展的激活能约为氢扩散激活能的一半,说明氢扩散可能是其控制过程。在高△K区和低△K区,温度对CF裂纹扩展的影响出现交叉现象,估计与腐蚀产物和断裂韧性的温度效应有关。在60℃和45℃两种温度下,蒸馏水中的CF裂纹扩展速率大于3.5%NaCl中的。文中还对产生这些结果的原因进行了探讨。更多还原

【Abstract】 The effects of temperature on corrosion fatigue (CF)crack propagation in aqueous solution environments for GC-4 (40CrMnSiMoVA) ultrahigh strength steel were investigated. Experimental results show that the activation energy of CF crack propagation in plateau region (medium △K region) of da/dN vs △K curves in 3.5% NaCl solution for GC-4 steel is approximately equal to one half of the hydrogen diffusion activation energy. It means that CF crack propagation may be controlled by hydrogen diffusion process. In high △K region and low △K region,intersection of da/dN vs △K curves at different temperatures was observed, which may be associated with the effect of temperature on corrosion product and fracture toughness. At 60℃ and 45℃,the CF crack propagation rate for GC-4 steel in distilled water is greater than that in 3.5% NaCl solution. The causes are also discussed.更多还原