scope:

Interest in the welding of ultra high strength steel sheet has been generated within the last several years by the requirement of the rocket motor case industry for a very high strength-to-weight material. For this reason virtually all recent activity in learning to weld these steels has been closely associated with the missile industry; this report is largely a summary of missile industry welding experience with these steels. The candidate base metal alloys for this classification (nominal yield strength greater than 200,000 psi) are discussed, and the reasons for the preference for the low alloy martensitic class is reviewed. The requirement for fracture toughness and resistance to multiaxial loading is important in this selection. A recently developed type, the high nickel maraging steels, shows promise in preliminary analysis of better meeting these requirements, and is discussed.