Stress Corrosion of Steam Turbine Disc and Rotor Steels

Abstract

Abstract A range of low alloy steels, commonly used in the construction of steam turbines, has been tested for susceptibility to stress corrosion cracking (SCC) in pure condensing steam and pure water. It has been shown that when tested for prolonged periods, the steels will initiate cracks in steam only at very high stresses. Initiation is promoted by stagnant conditions and retarded by residual compressive stresses. Propagation rates of cracks are low but increase as the strength level of the steel is raised. A low strength molybdenum free steel is much more resistant to stress corrosion than any of the other steels examined.