Effects of Mn and Ni on Microstructure and Mechanical Properties of Welded Joint of FV520(B) Steel

Medium carbon ferromanganese and nickel powders were added to the electrode coating of low hydrogen type basic slag system,and a special core wire used for FV520(B) steel was adopted in the welding test.The effects of alloy elements Mn and Ni on microstructure of weld seam and mechanical properties of joint of FV520(B) steel were analyzed through a series of experiments.The results show that austenitic alloy elements Mn and Ni can be transferred to the weld seam by adding medium carbon ferromanganese and nickel powders to the electrode coating.With the increase of alloy element contents,the microstructure of weld seam is refined,and martensitic layer is finer.Adding medium carbon ferromanganese and nickel powders all can increase the austenite content in the weld seam,and the former is better.The increasing of the austenite content in weld seam can improve the impact toughness of welded joint without lowering the strength.