THE CO2-LASER HARDFACING OF MOLD STEEL

Our studies show the CO2 laser hardfacing of P20 mold steel. increases the wear resistance of the mold. Hardfacing filler powder made of nic kel coated aluminum was fed into a pool of molten P20 mold steel. Wear testing, microhardness measurement, metallographic examination, x-ray diffraction analysis, and SEM-EDX analysis were carried out in order to understand the relationship between the microstructures and wear pr operties of the hardfacing specimens. The results of x-ray diffraction analysis showed that NiAl compound was formed on the surface of the h ardfacing layer made at a scanning speed of 5 mm/sec along with a powe r input of 1.2 KW. The wear resistance of the hardfacing specimen was noticeably improved by the presence of NiAl particles.