高温塑性变形中裂纹修复的细晶效应

Tiny Particular Effect in Crack Self - Recovering Pro- cesses of Plastic Deformation

为了探索高温塑性变形过程中裂纹修复规律,采用高温物理模拟方法研究了20MnMo材料内部孔隙性裂纹的变化过程。实验中发现20MnMo材料裂纹修复过程中普遍存在细晶现象,研究了温度、外压和时间等因素对其影响,揭示了细晶形成的原因及其在修复中的地位。根据其变化将裂纹修复分为3个阶段,细晶现象可以作为缺陷修复程度的判据,并证明了再结晶是裂纹修复的主要原因。对缺陷修复规律在生产实际中应用具有重要的指导作用。

In order to discover the crack self -recovering rule in the process of plastic deformation . the recovering law and reliability of internal cavities cracks in alloy 20MnMo were investigated by modeling. Tiny Particular Effect in the crack recovering process was discovered by experiments. The effects of temperature, time, and outside compressive stress on Tiny Particular Effect were investigated. The arising reason and transformation of the Tiny Particular Effect were described. The process of crack self - recovering was divided into three phases according to Tiny Particular Effect. Recrystallization being the primary matter of crack self - recovering was set forth for the first time. The effect can be used as criterion of self - recovering. It directed how the crack self-recovering rule was used in practice.