Abstract: Corrosion fatigue crack growth behaviors in a high strength steel (20SiMn2MoV) subjected to various stress ratios (R=0.2, 0.3, 0.5, 0.8) loading, while immersed in saline water (3.5% NaC1) or distilled water, were observed. The testing results indicat that stress ratio has an important effect on both da/Dn-△K curves and crack propagation mechanisms. Based upon it, the corrosion fatigue crack propagation mechanism map (CFCPM map) with Km(=0.5(Kmax+Kmin)) versus △K as coordinates has been built up. Criteria for the changes from one corrosion fatigue mechanism to another are presented in CFCPM map and discussed.

Key words: 腐蚀疲劳, 高强度钢, 裂纹扩展