SS400강에서 CO2, Ar가스의 변화에 따른 열영향부의 파괴검사에 관한 연구

A Study on the Fracture Strength of CO2, Ar Gas HAZ(Heat Affected Zone) in SS400 Steel

We investigate the welding characteristics, mechanical properties, stress in tensity factor, fracture strength, and microstructure in the HAZ of the SS400 steels which were welded at different heat inputs using solid wire in the CO2 gas and Ar gas welding system. A welding machine which is consisted of welding gun, wire, CO2 gas, carriage unit for welding machine, and table system for welding machine was developed to evaluate the characteristics. the relation between voltage and current shows phenomenon. The weld condition through voltage is increasing and is increased according to the current. The microstructure of base metal, fusion zone, and HAZ were not much different between CO2 gas and Ar gas. In this study, the weld-ability and weldment characteristics of SS400 steel are considered in several shieling gases(CO2 100%, CO2 80%+Ar 20%, CO2 60%+Ar 40%, CO2 50%+Ar 50%, Ar 100%)in viewpoint of welding productivity.