Austenitic stainless steels layers deposited by laser cladding on a mild steel : realization and characterization

The present work reports on 18-10 (AISI 304 grade) and 18-12-Mo (AISI 316 grade) stainless steel coatings produced by laser powder cladding technique. Clad layers of uniform thicknesses have been produced through partially overlapping single cladding tracks. The clad layers thus obtained show excellent adherence, few porosities and good chemical homogeneity. The microstructure is dendritic or most often cellular. The 304 clad layers are free of cracks and have a structure mainly austenitic with a certain amount of [MATH]. The 316 clad layers show always cracks and their structure is almost fully austenitic. Primary solidification of [MATH] phase seems thus favourable to prevent hot cracking of the austenitic stainless steels layers. The corrosion resistance of the crack-free 304 clad layers has been tested in various saline media. In every case, the coatings exhibit a very good uniform corrosion resistance

Microstructural and electrochemical characterization of laser deposited 18-10 austenitic stainless steel clad layers

The present work reports on 18-10 stainless steel coatings produced by laser powder cladding technique on a mild steel. Uniform clad layers - about 600 µm thick - have been produced through partially overlapping single cladding tracks. The clad layers thus obtained show excellent adherence, no cracks, few porosities and good chemical homogeneity. The microstructure is dendritic or cellular. Dentrites or cells have an austenitic structure and a small amount of δ-ferrite is detected in the interdendritic areas. The corrosion resistance of the clad layers is tested by electrochemical techniques in various neutral or acidified aqueous saline media, deaerated or naturally aerated. In every case, the coatings show an excellent uniform corrosion resistance