QUENCH AND TEMPER CORROSION RESISTANT STEEL ALLOY

摘要

A quench and temper steel alloy is disclosed having the following composition in weight percent. C 0.2-0.5 Mn 0.1-1.0 Si 0.1-1.2 Cr 9-14.5 Ni 3.0-5.5 Mo 1-2 Cu 0-1.0 Co 1-4 W 0.2 max. V 0.1-1.0 Ti up to 0.5 Nb 0-0.5 Ta 0-0.5 Al 0-0.25 Ce 0-0.01 La 0-0.01 The balance of the alloy is iron and the usual impurities including not more than about 0.01% phosphorus, not more than about 0.010% sulfur, and not more than about 0.10% nitrogen. A quenched and tempered steel article made from this alloy is also disclosed. The steel article is characterized by a tensile strength of at least about 290 ksi, a fracture toughness (KIc) of at least about 65 ksi, good resistance to general corrosion, and good resistance to pitting corrosion.