Effect of Welding Wires on Microstructure and Mechanical Properties of CO2 Shielded Arc Welding Welded Joint of 30CrMnSiA Steel

30CrMnSiA steel is welded by CO2 shielded arc welding with H08Mn2SiA and Ok Aristorod 12.5 welding wire respectively. The effect of welding compositions on the microstructure and mechanical properties of welded joint are studied. The results show that using Ok Aristorod 12.5 for welding, the microstructures of weld metal are mainly composed of acicular ferrite, proeutectoid ferrite and pearlite, the tensile strength of the welded joint is poor. When using H08Mn2SiA for welding, the microstructures of weld metal are mainly composed of fine grain ferrite and acicular ferrite, the acicular ferrite is refined and the content of acicular ferrite is increased, so the tensile strength of the welded joint is improved. Using these two welding wires are welded, the joints both have excellent bending properties.