Selective Laser Melting of Stainless Steels: A review of Process, Microstructure and Properties

Metal additive manufacturing is revolutionizing how we produce and use materials. Selective Laser Melting (SLM) is one of the most popular additive manufacturing techniques for creating high-performance metal components. Stainless Steel is preferred for additive manufacturing due to its powder form availability, low cost, mechanical properties, and corrosion resistance. However, the complex thermal history and rapid solidification in the SLM process led to an out-of-equilibrium microstructure of resulting components, which can affect their mechanical properties. To better understand the relationship between processing, microstructure, and properties, exploring and enhancing SLM-fabricated stainless-steel components is essential. This review comprehensively overviews the selective laser melting process, key processing parameters, and commonly encountered defects. Furthermore, the study presents a detailed discussion of microstructure, mechanical behavior (including hardness, tensile, and fatigue properties), and corrosion resistance of all SLM-manufactured stainless steel grades, along with the effects of various post-process treatments. This paper reveals that the SLM process can produce stainless steel with satisfactory performance that may exceed conventionally processed materials. However, the final section highlights the challenges and research gaps in this field that must be addressed.