PROCESSING AND PROPERTIES OF DUPLEX STAINLESS STEEL COATINGS MANUFACTURED BY COAXIAL HOT-WIRE LASER CLADDING

摘要

Duplex stainless steels are used for example in pulpand paper industry, chemical plants and offshoreplatforms. The advantages of duplex stainless steelsare high resistances to pitting corrosion, stresscorrosion cracking and corrosion fatigue. Theexperimental tests using Thermanit 2509 super duplexwire were performed with coaxial laser wire claddinghead. Thermanit 2509 is austenite-ferrite stainless steelFe-25Cr-10Ni-4Mo with high amount of alloyingcontents with excellent corrosion resistance. Corrosionproperties of duplex hot-wire laser coatings wereinvestigated by the critical pitting temperature (CPT)test. CPT values of duplex laser coating specimenswere measured nearly consistent with 2507 wroughtduplex steel. Microstructure phases of laser duplexcoatings were investigated and compared to theobjective 50-50% austenite-ferrite ratio.