Microstructure and properties of annular coaxial powder feeding TIG cladding layer doped with SiC for 316L stainless steel

TIG cladding is an economical and efficient surface repair method. Compared with the traditional preset powder method, coaxial powder feeding method has excellent adaptability, but there are relatively few experimental studies. The annular coaxial powder-feeding TIG cladding torch was designed and manufactured independently. Compared with the tubular coaxial powder-feeding TIG cladding torch, the cladding layer manufactured has no defects such as arc extinguishing position pit, uneven weld seam and inconsistent weld seam width, and has higher cladding efficiency. By optimizing the parameters of welding line energy, powder feeding and SiC concentration, TIG cladding with annular coaxial powder feeding was carried out on the surface of 316L stainless steel, and single-layer single-pass cladding and single-layer multi-pass cladding with excellent appearance were obtained. The microhardness measurement, microstructure and element composition analysis, macro electrochemical corrosion test, micro electrochemical corrosion test and wear resistance test of the cladding layer were carried out, and compared with the base metal. The research shows that the SiC powder introduced by the annular coaxial powder feeding TIG effectively improves the corrosion resistance and wear resistance of the cladding layer.