50Mn18Cr4WN奥氏体钢的应力腐蚀和氢致开裂

STRESS CORROSION CRACKING AND HYDROGEN INDUCED CRACKING BEHAVIOURS OF AUSTENITIC STEEL 50Mnl8Cr4WN

本文采用悬臂弯曲预裂纹试样应力腐蚀试验方法和紧凑拉伸试样恒载荷法测定了５０Ｍｎ１８Ｃｒ４０ＷＮ奥氏体钢在含Ｃ１－和ＮＯ３－的水溶液中应力腐蚀以及电解充氢条件下氢致开裂的门槛值，并对应力腐蚀和氢致开裂的裂纹走向与断口形貌进行了观察．５０Ｍｎ１８Ｃｒ４ＷＮ钢在含Ｃ１－和ＮＯ３－的水溶液中均能产生应力腐蚀开裂，且在含ＮＯ３－的水溶液中比在含Ｃ１－的水溶液中应力腐蚀敏感性大．在电解充氢条件下，５０Ｍｎ１８Ｃｒ４ＷＮ钢也能产生氢致开裂．

The threshold values of SCC in chloride and nitrate aqueous solutions and HIC under dynamical hydrogen charging for steel 50Mnl8r4WN were determined using pre-cracked cantilever bend specimens and compact tension specimens.Observations of crack propagation and fracture morphologywere carried out by optical microscope and SEM respectively.The results indicate that the steel is much more sensitive to SCC in nitrate aqueous solution than in chloride.