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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 37CrNi3 steel after eliminating the pre-treatment of coarse overheating and temper brittleness at the same time the fracture phenomenon was studied. The results showed that the genetic phenomenon of this fracture was related to segregation along the austenite grain boundaries during the heating by overheating. That pre-treatment, along the coarse austenite grain boundaries with P, Cr, Ni and other elements of the segregation, reheating to 850 ℃ can not eliminate this segregation. When the steel is tempered slowly after high temperature tempering, the segregated Cr and Ni will promote segregation of P along the original coarse austenite grain boundaries. When low temperature tempering, there may be more carbides along the coarse austenite grain boundaries Precipitation. All these will lead to fracture along the original coarse austenite grain boundary, causing fracture genetic.