15Mn钢在3.5％氯化钠水溶液中的腐蚀疲劳

FATIGUE CRACK GROWTH OF 15Mn STEEL IN 3.5％ NaCl SOLUTION

研究了不同组织状态的15Mn钢在3.5％氯化钠水溶液中的疲劳裂纹扩展行为,测定了裂尖区的平均氢含量和裂纹闭合力,发现外部条件(力学及环境)和材料的显微组织对腐蚀疲劳有重要影响。结合断口和裂纹走向观察,提出了15Mn钢腐蚀疲劳断裂的复合机制和断裂机制图。

The crack growth of 15Mn steel with various microstructures in 3.5％ NaCl solution was investigated, It is found that the microstructures of steels have Considerable influence on corrosion fatigue. With increasing Stress intensities,crack closure effect decreases and average hydrogen content at crack tip increases. The fracture modes vary from striations to intergranular fracture and then to quasi-cleavage fracture with crack growth. The relation between electrochemical conditions and mechanical variables is discussed. The componund mechanisms of corrosion fatigue are proposed. A fracture-mode-map of 15Mn steel is worked out.