Microstructure and Properties of Laser Surface Alloying 304 Stainless Steel with Si

Silicon was added to the surface of 304 stain-less steel by laser melting the sprayed preplaced Sipowders.The optical microscopy,X-ray diffractionand EPMA were employed to investigate themicrostructure and chemical composition of thelaser surface alloyed layer.The hardness of the al-loyed layer was measured by microhardness testand wear resistance was evaluated by scratch test.Corrosion resistance of laser alloyed sample wasstudied in 1N H_2SO_4+0.1N NaCl and0.5N HCl+0.5N NaCl aqueous solutions.Amicrocrystalline intermetallic compound coatingwith smooth surface and good chemicalhomogeneity without porosity and crack is ob-tained.The hardness is about 720 HV.The wear re-sistance is 2 times better than that of the substrate.The corrosion resistance of the laser alloyed sampleis much better than that of 304 stainless steelsample.

Microstructure and Properties of Laser Surface Alloying 304 Stainless Steel with Si

Silicon was added to the surface of 304 stain- less steel by laser melting the sprayed preplaced Si powders.The optical microscopy,X-ray diffraction and EPMA were employed to investigate the microstructure and chemical composition of the laser surface alloyed layer.The hardness of the al- loyed layer was measured by microhardness test and wear resistance was evaluated by scratch test. Corrosion resistance of laser alloyed sample was studied in 1N H_2SO_4+0.1N NaCl and 0.5N HCl+0.5N NaCl aqueous solutions.A microcrystalline intermetallic compound coating with smooth surface and good chemical homogeneity without porosity and crack is ob- tained.The hardness is about 720 HV.The wear re- sistance is 2 times better than that of the substrate. The corrosion resistance of the laser alloyed sample is much better than that of 304 stainless steel sample.