DISCOVERY OF INNER CRACK RECOVERY AND ITS STRUCTURE CHANGE IN 20MnMo STEEL
20MnMo钢内裂纹修复现象的发现及其金属组织的变化

By physical modelling, the recovery phenomenon of inner crack in 20MnMo steel at high temperature was discovered, and its regular pattern was concluded.It was believed that the recovery process was mainly controlled by the diffusion and migration of metal atoms. The recovery process can be divided into two steps, void filling and grain growing. The filling materials consisted of many very fine grains with segregation of iron. There was a very clear boundary between the filling materials and matrix. The grain growing and composition homogenzing occurred simultaneously. Inner cracks and voids can be filled and taken away in a certain deformation. A certain holding time was necessary for grain growing and inner crack recovery entirely.