SURFACE MECHANICAL-PROPERTIES OF AN EXPLO SIVE TREATED STAINLESS-STEEL

A new surface treatment technique by primary explosive was used on a 3 16L type austenitic stainless steel. Two explosive compositions, induc ing a pressure of 1 GPa and 4 GPa respectively, were deposited in a th in layer on plane samples. The detonation induced effects have been ch aracterized by different techniques. The surface roughness increases w ith the applied pressure. but remains lower than that obtained after s hot peening. The microhardness profiles along a direction perpendicula r to the treated surface and the microstructural study exhibit a marke d hardening on several hundred micrometers associated with a profuse t winning. Moreover, for the 4 GPa pressure a very thin surface layer of fine recrystallized grains appears. In both cases, tensile residual s tresses are measured at the surface and compressive stresses beyond 10 mum. The microstructure in the surface layers results of a noticeable thermal effect. The wear resistance of this stainless steel is improv ed by a factor 10 to 200 depending on the treatment conditions.