STEEL ALLOY WITH HIGH STRENGTH, HIGH IMPACT TOUGHNESS AND EXCELLENT FATIGUE LIFE FOR MUD MOTOR SHAFT APPLICATIONS.

摘要

A steel alloy is disclosed that provides a unique combination of strength, toughness, and fatigue life. The steel alloy has the following composition in weight percent. C about 0.15 to about 0.30 Mn about 1.7 to about 2.3 Si about 0.7 to about 1.1 Cr about 1.85 to about 2.35 Ni about 0.5 to about 0.9 MO+1/2W about 0.1 to about 0.3 Cu about 0.3 to about 0.7 V+5/9xNb about 0.2 to about 0.5 The balance of the alloy is iron, usual impurities, and residual amounts of other elements added during melting for deoxidizing and/or desulfurizing the alloy. A hardened and tempered steel article made from the alloy is also disclosed.