Microstructure and mechanical properties of E36 steel joint welded by underwater wet welding

The microstructure and mechanical properties of E36 steel joint welded by underwater welding using flux-cored wire are comprehensively investigated.The welding depth,welding current and welding voltage is 4 m,130 A and 32 V,respectively.The weld metal is ferrite which varies in size,with carbide particles distributed on it,while the microstructure of HAZ is mixture of martensite of different size and some tempered structure.The microhardness of the weld metal is 190 HV.Almost all the tensile specimens fracture in weld metal and the average tensile strength of joint is 390 MPa,which is equal to 80%that of base metal.The tensile fracture morphology of joint presents obviously the characterization of brittle fracture,which displays the features of cleavage fracture and intergranular fracture.