Improving of mechanical properties of GX8CrNi25-21 grade austenitic stainless steel

In this study, GX8CrNi25-21 material was produced by casting. The material was subjected to heat treatment by being exposed to four different temperatures and six different cooling intensities. The effects of heat treatment on primary and secondary carbide concentration, carbide distribution, and carbide type were investigated. As a result of abrasion tests, the behavior of the material against thermal shocks and wear resistance were determined and the most suitable heat treatment conditions were tried to be determined. It was determined that increasing the cooling intensity after the homogenization heat treatment applied to the material decreased the hardness. It was determined that the reason for the increase in hardness was not due to the martensitic transformation in the structure, but was related to the secondary carbide content in the structure. After the homogenization heat treatment, the carbide structure and distribution in the structure differed. The size of the primary carbides decreased and their distribution became homogeneous. Secondary carbides dispersed into smaller and equiaxed grains were formed in the matrix. It was determined that the hardness and volume ratio of carbide determined the wear rate.