LASER HARDENING OF TURBINE BLADES

Abstract

ABSTRACT This paper briefly describes our theoretical and experimental work on the laser heat treatment of the surfaces of martensitic stainless steel turbine blades. A hardened zone, very small in thickness compared to the blade, has been obtained without melting the substrate or reducing its hardness. A large spot with a high density power (as calculated by ad hoc thermal models) was necessary to treat each blade in a single pass; consequently a high power (15 kW) laser was used. Good metallurgical results were obtained with a total absence of cracks, porosity or other defects.