Internal crack recovery of 20MnMo steel

According to the results of physical modelling, SEM and SAM analysis of 20MnMo steel samples, internal cracks of metal parts are recoverable. The motive power of the recovery is atom diffusion and migration from matrix to voids. The recovery process consists of two steps. In the first step, the void area is filled up with a kind of metal mass, beginning from the crack tip. There are many microvoids in the mass with different microstructure from the matrix. In the second step, microvoids decrease in size and number, and the mass microstructure approaches the matrix, with the heating temperature increasing and the holding time prolonging. Recovery tests on rejected heavy forgings are successfully processed. It is believed that the recovery technique is a potential method for improving the internal quality and reducing the production loss and cost of metal products. Similar method can be used to treat other metal construction parts for rescuing them or prolonging their service life. Further research and de