Microstructural Evolution and Mechanical Enhancement in SCM440 Steel Through Gas Tungsten Arc Welding Cladding

This study explores the microstructural evolution and mechanical enhancement of SCM440 low alloy steel through gas tungsten arc welding multilayer cladding with aluminum filler material. The primary focus is on improving the surface properties, particularly hardness and wear resistance, by forming Fe‐Al intermetallic compounds. The investigation shows that the formation of Fe 3 Al and FeAl 3 intermetallic phases significantly increases hardness up to 2.8 times higher than the base material. Through detailed microstructural analysis using scanning electron microscopy and energy dispersive x‐ray spectroscopy, the results indicate that heat input and cooling rates play a critical role in the formation of refined grain structures and intermetallic distribution. Optimized heat input enhances mechanical properties by promoting uniform phase growth while avoiding the overgrowth of brittle compounds and the formation of unmixed zones. The findings provide valuable insights for optimizing welding parameters to achieve a balance between hardness and ductility in industrial applications where wear resistance is critical.