摘要
对37CrNi3钢经消除了预处理粗大过热组织后与回火脆性同时出现的断口遗传现象进行了研究。结果表明这一断口遗传现象与过热淬火加热时沿奥氏体晶界发生的偏聚有关。即预处理时,沿粗大奥氏体晶粒边界有 P、Cr、Ni 等元素的偏聚,再次加热到850℃不能消除这种偏聚。高温回火后缓冷时,已偏聚的 Cr、Ni 将促进 P 沿原粗大奥氏体晶粒边界偏聚,低温回火时有可能有较多的碳化物沿粗大奥氏体晶粒边界析出。这些都将导致断裂沿原粗大奥氏体晶粒边界发生,引起断口遗传。
The fracture surface inheritance phenomena after eliminating overheated rough structure and with the tempering brittleness occurring at the same time were investigated in 37CrNi3 steel.It was found that the fracture surface heredity was related to the segregation along the austenite boundaries at overheating of pre-treatment,the elements P,Cr,Ni etc segregated along coarse austenite boundaries of pre-treatment,and this segregation could not be eliminated by second beating at 850℃.When cooling at slower rate from higher tempering temperature,the segregated Cr,Ni would promote P to segregate along the coarse austenite boundaries.When tempering at lower temperature more carbonites could precipitate along the coarse austenite boundaries.The above changes would result in the cracking along the rough austenite boundaries, that is fracture surface inheritance occurred.
基金
国家自然科学基金
关键词
断口遗传
37CrNi3钢
机制
fracture surface heredity
boundary segregation
tempering brittleness
