Wear Resistance Improvement of a 316L Austenitic Stainless Steel Treated by an Explosive Thin Film

A surface treatment technique by primary explosive was used on a 316L type austenitic stainless steel. Two explosive compositions, inducing a pressure of 3 GPa and 6 GPa respectively, were deposited in thin layer on flat samples. The residual microstructure is characterized by a profuse twinning whose density depends on the applied pressure and the depth below the treated surface. Moreover for the 6 GPa pressure a very thin surface layer of recrystallization in fine grains appears. The wear tests were performed on a pin on disc tribometer with loadings of 0.5 N and 4 N. In both cases, the wear resistance improvement reaches a factor of about 10 for the lower pressure and a factor 200 for the higher pressure. However, in the last case, the wear resistance improvement depends on the thin recrystallized layer leading to a benefit of a factor of 10, and mainly to the very thin layer of lead deposited by the treatment which acts as a solid lubricant.