Development Of Nickel-Based Electrode ENiCrMo-3 And Research Of Deposited Metal

With the development of modern industry,the demand of material is harsher.In order to meet with the different requirements,people pay more attention to the research and development of new materials.And the welding consumble matching the material have also been developed.The product series and varieties of welding consumble have been progressive.The special and efficient welding consumble are widely used,especially the stainless steel and nickel based alloy welding materials.Nickel based alloy is recognized as the best corrosion resistant materials,which can be used in different kinds of harsh environments.Nickel based alloy has poor weldablity,such as bad welding usability,hot cracking and porosity.It is very important and necessary to improving the weldablity.In the paper,the electrode ENiCrMo-3 of Inconel 625 is successfully developed.And the welding usability,hot cracking susceptibility,mechanical properties and high temperature oxidation of the electrode are been researched.The slag system of CaO-CaF₂-SiO₂-TiO₂ has been used.The influence of diferent raw material,such as marble,rutile,fluorite and quartz,for arc stability,spatter,and slag detachablity has been researched.And the optimum amount of raw materials has been made in the electrode coating,which makes the electrode with the good welding usability.Four different formulas of electrodes were designed to study the effects of Mn,Cr,Mo and Nb elements on the mechanical properties,high temperature oxidation resistance and thermal crack resistance of deposited metal.The microstructure of ENiCrMo-3 deposited metal is cast structure.The weld bead structure is fine,mainly composed of austenite matrix and the precipitated phases.These phases are massive,strip and bits.The Mn,Cr,Mo,Nb content of the deposited metal,which adjusting in the range of the national standard,are not affects the tensile strength of welding electrode.When the content of Nb is in the limit of national standards,the extension rate is lowest,which lower than the minimum requirements of the national standards.When the content of the four elements is located in the middle of national standards,the elongation rate is highest.The performance of high temperature oxidation shows that ENi CrMo-3 deposited metal has good oxidation resistance.Increasing oxidation time,oxidation rate gradually become very slow.High temperature oxidation resistance of deposited metal increases with the increase of Mo,Cr and Nb content,and decreased with the increase of Mn content.The chemical composition and mechanical properties of ENiCrMo-3 nickel based electrode reached AWS5.11,GB/13814 and other related standards.Compared with the other company product,the welding performance,thermal crack resistance andhigh temperature oxidation resistance of electrode deposited metal are better than the other,which meeting with the expected goal of development.