Features of Local Corrosion of AISI316L Steel Manufactured by Selective Laser Melting

Abstract

Regularities of corrosion damage in the case of pitting and gap corrosion are studied on samples of austenitic stainless steel (AINSI 316L) produced using the powder selective laser-melting (SLM) technique. It is found that the corrosion rate and the appearance of corrosion damage considerably depend on the surface state and heat treatment. Heat treatment (austenitization) results in a decrease in the local corrosion rate by 20–25%, a decrease in the number of pittings, and smoothing of the crevice corrosion profile as compared to the initial SLM state. The opening of the subsurface pores in the course of machining somewhat decreases corrosion resistance. It is shown that the initiation and development of pitting and crevice corrosion are related to the presence of surface and subsurface pores in the SLM material.