Effect of laser and heat treatment on the structure and properties of high-chromium cast iron

Abstract

The authors investigate the effect of continuous radiation of a CO/sub 2/ laser in combination with standard heat treatment on the structure, phase composition, and properties of the wear-resistant high chromium cast iron IChKh16NMFTL. To compare the results of the effect of laser and heat treatment, the authors subjected specimens after quenching at 900/sup 0/C in oil together with laser treatment also to additional heta treatment: normalization, normalization with subsequent tempering at 250/sup 0/C 3 h, tempering along at 250 and 550/sup 0/C 3 h. Metallographic analysis was carried out with microscopes ''EPITYP-2'' and NUM-1, x-ray diffraction analysis on an installation URS-50IM in chromium K /SUB alpha/ radiation. It was established that in laser treatment with preliminary heating, the temperature at which cracks begin to appear depends on the direction in which the beam moves over the surface of the specimens. Thus, as a result of the investigations, it was established that hardening of wear-resistant cast iron IChKh16NMFTL is attained by the precipitation of disperse carbides (Cr, Fe)/sub 7/C/sub 3/ from the martensitic matrix.