Study On Self Shielded Flux Cored Wire For Dual Phase Stainless Steel 2205 And Microstructure And Performance Of Weid Metal

Compared with ferritic stainless steel,dual phase stainless steel has good plasticity and toughness,no brittleness at room temperature and high thermal conductivity.Its yield strength is higher than that of austenitic stainless steel.It has been widely used in petroleum,chemical,energy,shipbuilding and other fields.SSFCE combines the efficiency of continuous welding and convenient without gas protection,So it can become the most promising and new generation of welding materials and can replace solid wires and rods.The development of self shielded flux cored wire for double phase stainless steel is of great significance.Firstly,in this paper,the self shielded flux cored wire of slag was studied based on the powder component,slag morphology,composition,formation things.And then,adding in the flux cored wire with different Ni/Cr ratios,to adjust the welding material composition,the influence on the mechanical properties of weld metal by microstructure evolution was studied.Finally,research the resistance corrosion in two different acidic medium of the duplex stainless steel and its weld metalThe fluorite,titanium dioxide,quartz and marble of flux cored wire exert certain influence on removal slag,in which,titanium dioxide has a beneficial effect on removal slag,and fluorite,quartz,marble have adverse effects.The CaF2 in slag is retained from the flux cored wire,other components are all the salts and oxidesin from the high temperature chemical metallurgy reaction in the welding process.The main products include CaTiO3,Ca2SiO4,MgAL2O4,MnO,Al2O3-SiO2,MnO SiO2These weld microstructures of four kinds of different Ni/Cr addition in flux cored wire are all austenite and ferrite structure.But the account and morphology of phases are different.With Ni/Cr adding ratio increasing,The austenite increased and ferrite reduced,the size of austenite increases.Its strength slightly decreased gradually,but the plasticity and toughness are substantially increased.In H2SO4 medium,the corrosion rate of the base matel is minimum,the weld without adding alloy elements is highest,the weld adding alloy elements is lightly higher than base metal.In HCl medium,duplex stainless steel and its weld show the selective corrosion,their corrosion rate is much higher than H2SO4.Among them,corrosion resistance of ferrite-dominant weld is poorer than that of base metal.Corrosion resistance of austenite-dominant weld is better than that of base metal..