MICROSTRUCTURE AND CORROSION RESISTANCE OF LASER SURFACE ALLOYING PLASMA SPRAYED Cr-Mo COATING

The precipitation of χ-phase,σ-phase and carbides may be restrained or eliminated by lasermelting the plasma sprayed Cr-Mo alloy coating,in which austenite of abundant block usual-ly occurred on medium carbon low alloying steels.The corrosion resistance of this coating to0.5mol/L H_2SO_4 was examined to be superior to that of 18-8 stainless steel.The laser al-loying Cr-Mo coating also has excellent resistance to pitting corrosion,and no pitting ap-peared even it immersed in a medium containing Cl~- ions.