Steel rotor shafts for electric machines

摘要

New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight: C 0.15 to 0.3% Si <0.1% Mn <1% Ni 3 to 5% Cr >2%, <3.5% (Mo+W) 0.1 to 1.0%, W being optional V 0.03 to 0.35%, and the remainder substantially Fe. Other aspects are also described.