Corrosion-resistant turbine blades and method for producing them

摘要

A turbine blade includes a core made of a highly heat-resistant alloy and a highly heat-resistant, nonporous, corrosion-resistant, metallic protective cover fitted onto the core. The cover forms a gas-tight metallurgical bond with the core and has great strength, high ductility and a uniform layer thickness. The process includes the steps of preshaping a core of highly heat-resistant material and fitting the preshaped core into a substantially preshaped, corrosion-resistant and highly heat-resistant cover. The cover is welded to the core at a point which during later use is subjected only to little stress to form a vacuum-tight seal and workpiece. The workpiece is heated in a pressure vessel to a temperature of at least 1000 DEG C, and the cover of the heated workpiece is heat-welded to the core by isotactic hot-pressing without the formation of pores.