EFFECTS OF TEMPERING ABOVE THE LOWER CRITICAL TEMPERATURE Ac1 ON THE PROPERTIES OF AN HY-80 STEEL

摘要

The effects of tempering above the critical transformation temperature on the microstructure, notch-toughness and mechanical properties of HY-80 steel were investigated. The formation of alpha ferrite and prime marten site after tempering above the lower critical temperature and quenching will result in mechanical properties that fall below the requirements of the HY-80 specification. Retendering to achieve minimum yield strengths may result in nonuniform yield strength distribution. The possibility of under bead cracking due to alloy segregation is also discussed.