Laser hardening of high chromium steel

Abstract

1. Laser processing can be an effective mean of the surface hardening of high chromium martensitic class steel. The hardness of the laser hardened zones is more than 4 times bigger than that of annealed steel and in 30% higher than hardness of the steel thoroughly hardened by traditional heat treatment methods. 2. For high chromium ledeburitic class steel laser thermal processing is useful when it is necessary to have shallow hardened layers without remelting of surface. At this hardness of hardened layer exceeds that of annealed steel by 2.8...2.9 times and is as hard as steel thoroughly hardened by traditional methods of heat treatment. 3. Laser processing with the remelting of the surface increases the limit temperature of heat resistance of hardened layer of the high chromium martensitic class steel. For components that work in wear out conditions without striking and cyclic loading, the effect of the secondary (ageing) hardness can be used. 4. At the laser hardening of high chromium martensitic class steel, great inner stresses may occur. They may lead to fractures. The fractures occur in the heat affected zone on the border with the remelted zone of the metal.