Effect of Heat Input on Strength and Toughness of Welding Metal of High Strength Wire

With tensile and impact tests and microstructure observation,the effect of heat input(from 10 kJ/cm to 27 kJ/cm) on the strength and toughness of welding metal made by high strength welding wire was investigated.The results show that the strength and toughness decrease as the heat input increase.The reason lays to more loss of alloy elements,elongated cooling time of welding metal,more ferrite of low strength and tougness in high temperature reheating region as the heat input increase.