Ultra high strength, secondary hardening steels with superior toughness and weldability

摘要

High strength steel is produced by a first rolling of a steel composition, reheated above 1100° C., above the austenite recrystallization, a second rolling below the austenite recrystallization temperature, water cooling from above Ar.sub.3 to less than 400° C. and followed by tempering below the Ac.sub.1 transformation point.