Producing welds with properties matching those of the steel is achallenge at high strength levels. The present study investigated how coolingrates and dilution affects strength and toughness when welding steelswith yield strengths of 777 MPa and 1193 MPa. Overmatching weld metalstrength was achieved for the less strong steel and weld strengths >1000MPa were recorded for the stronger steel. Fracture in transverse tensile testingwas always located in base material or HAZ. Low dilution, rapid coolingand single pass welding contributed to higher strength. Impact toughnesswas higher for lower strength and low dilution.

Welding; high strength steels; strength; toughness; dilution