The Effect of Ni and Cu Addition on Mechanical Behavior of Thermomechanically Controlled Processed HSLA X100 Steels

Abstract

The effect of Cu and Ni addition on mechanical behavior of HSLA X100 steels containing relatively low amount of Carbon was studied. Very high strength, the appropriate level of toughness and good weldability attained through low carbon addition have made these steels a very attractive choice for the shipbuilding applications. Thermomechanical controlled processing was applied on the cast samples with various amounts of Cu and Ni, and the effect of process variables on mechanical properties were investigated. Austenitization and quenching together with tempering were also applied on the thermomechanically produced samples. Mechanical properties were evaluated by tensile, hardness and Charpy impact tests. Microstructural evaluation was done by Optical and Scanning Electron Microscopies. Results showed that by adding Ni and Cu up to 7.6% and 4.1%, respectively, it is possible to obtain yield strength above 160 ksi. This was achieved while toughness was still in an adequate level.