High-speed laser melt injection for wear protection of skin-pass rolls

Abstract

Laser melt injection (LMI) is a technology for producing metal matrix composite (MMC) layers on tools such as skin-pass rolls by injecting hard particles into a laser-induced weld pool. However, low process speeds prevent the application of laser melt injection on a large scale. To overcome this drawback, a new approach is presented: High-speed laser melt injection (HSLMI) is a promising method for generating highly wear-resistant MMC-layers on tools with high productivity. For the first time, high process speeds of up to 100 m/min were reached with HSLMI of spherical fused tungsten carbide (SFTC) particles into the steel 1.2362 that is used for skin-pass rolls. It was found that both the crack susceptibility and the SFTC dissolution can be reduced significantly by increasing the process speed. The wear behavior of the MMC layers was studied in a pin-on-plate test. It was found that the SFTC reinforcement leads to a significant improvement in wear resistance over the non-reinforced steel substrate. The wear volume was reduced from 3.6 mm³ to 0.1 mm³ to 0.3 mm³ by an SFTC particle-reinforcement.