A novel wire arc additive manufactured process for 316L stainless steel for pressure vessel applications: Microstructure, mechanical properties and corrosion behaviour

Wire Arc Additive Manufacturing (WAAM) offers unprecedented design freedom and manufacturing flexibility for producing large and complex components. Additive-assisted WAAM processes, including ultrasound, in-situ rolling, and stir-friction, offer certain advantages over traditional WAAM. Nevertheless, these technologies cannot eliminate the inherent costs associated with increased production. Thus, there is an urgent need for a low-cost and efficient production method. In this study, WAAM assisted by a rapid cooling device was employed to fabricate 316L stainless steel, comparing the effects of rapid cooling in constant-temperature water with natural air cooling on microstructure, mechanical properties, and corrosion resistance. The results demonstrate that rapid cooling improved productivity fivefold. Compared to WAAM, 24IRC-WAAM (24 °C interlayer rapid cooling-wire arc additive manufacturing) and 60IRC-WAAM (60 °C interlayer rapid cooling-wire arc additive manufacturing) exhibited average grain refinement of 70.31 % and 57.22 %, respectively, reducing the material's internal anisotropy and significantly enhancing both horizontal and vertical mechanical properties, as well as corrosion resistance. Studies further indicate that the preparation of 316L using arc additive manufacturing in water at 60 °C is a cost-effective process, with the mechanical properties and corrosion resistance of WAAM 316L being comparable to those of forged grades, making it suitable for pressure vessels that demand high corrosion resistance.