高锰奥氏体超低温钢低温脆断机制的研究  

STUDY ON LOW TEMPERATURE BRITTLE FRACTURE OF HIGH MANGANESE AUSTENITIC CRYOGENIC STEELS

作　　者：薛侃时[1] 王滨[1] 李晋[1] 张静江[1] 奚建法[1] 孙大涌 

机构地区：[1]机械工业部上海材料研究所 [2]机械工业部机械科学研究院

出　　处：《机械工程学报》1998年第5期1-6,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金;机械工业技术发展基金

摘　　要：研究了高锰奥氏体钢的低温断裂机制。高锰奥氏体钢随温度降低其断裂机制由韧窝状断裂转变到晶界断裂。在固溶处理时快速冷却过程中锰在奥氏体晶界产生不平衡偏聚。由于锰的偏聚层的强度、应变硬化指数和应变硬化率均高于晶内基体材料，因此在加载形变过程中位错在偏聚层处塞积而产生很大的内应力，在偏聚层处的应力远大于晶内，因此在晶界偏聚层处产生晶界断裂。The low temperature fracture mechanism of high manganese austenitic steels is studied. High manganese steels undergo a ductile to brittle transition at low temperature, which is accompanied by a change in the fracture mechanism from dimple fracture to intergranular fracture. During the fast cooling process of solution treatment, nonequilibrium segregation of manganese was produced at austenite grain boundaries. Due to the strength, strain hardening exponent and strain hardening rate of manganese segregation zone are higher than that of matrix, therefore, dislocations pile up at the segregation zone and produce higher internal stress during loading and deformation. Since the stress at the segregation gone are much greater than that of matrix, thus, the high stress causes intergranular fracture at grain boundary segregation zone.

关 键 词：高锰奥氏体 超低温钢 晶界断裂 低温 脆断 

分 类 号：TG142.25[一般工业技术—材料科学与工程]