Comparative Study of Microstructure, Tensile Strength and Corrosion Resistance of 316L Stainless Steel Produced via Novel Resistance Weld Additive Manufacturing and Wire Arc Additive Manufacturing
摘要
316 L stainless steel is among the most widely used steel grades in various industries, including petrochemical, food processing, marine, and medical, due to its excellent corrosion resistance, good weldability and recyclability. Wire arc additive manufacturing (WAAM) offers advantages such as low cost and high deposition rates; thus, WAAM is considered a feasible additive manufacturing (AM) process for many steel materials. However, as-deposited additively manufactured stainless steel components have inferior mechanical properties due to various defects, such as porosity, solidification cracking, distortion, and high surface roughness, making them incompatible with extreme environments where these defects can lead to failure. In this study, a novel resistance welding additive manufacturing (RWAM) has been used to fabricate builds of 316 L stainless steel. The builds were fabricated using resistance spot welding to join the five sheets using welding currents of 150, 175 and 200 kA at constant welding time and electrode pressure. The RWAM fabricated builds microstructure, tensile strength and corrosion resistance were compared with the WAAM fabricated build. The results indicated that the RWAM-L3 build sample made at a welding current of 175 kA exhibited 420% (i.e., 26 kN) higher strength than WAAM build sample (i.e., 5 kN). The results also showed that corrosion rate of RWAM-L3 build sample was 40% less (11.13 mpy) than WAAM build sample (18.57 mpy). The better strength and corrosion resistance of RWAM-L3 build is attributed to its lower microstructural heterogeneity and porosity compared to WAAM build.