Research On A-TIG Welding Of Superalloy GH4169

Superalloy is a kind of material which can work for a long time under the condition of high temperature of 600? and certain stress.The alloy has good properties including high temperature strength,oxidation resistance,corrosion resistance,fatigue property,fracture toughness and plasticity,and has good structure stability at various temperatures.So it has been widely used in aviation,aerospace,chemical industry and energy.With the development of the industry and the higher requirements for the material,welding has become an important way to connect materials.TIG welding,electron beam welding,brazing and friction welding.Different welding methods have different advantages and disadvantages.At present,the welding methods of GH4169 alloy can be divided into two types: one is the wide application of tungsten inert gas welding(TIG),the other is laser welding.However,the TIG welding penetration is shallow,easy to produce porosity,welding cracks and other defects,and the high cost of laser welding,the depth of melting,the requirements of the assembly is high,generally used for thin-walled castings.These two kinds of welding methods severely limit the application of the alloy in practical production.Active tungsten argon arc welding(A-TIG),compared with TIG welding,has the advantages of greatly increasing the penetration depth and reducing the welding crack,so consider using A-TIG instead of TIG welding.In this paper,the influence of different active agents on the weld penetration was studied.The composite active agent was set up.The results show that in the same welding parameters of A-TIG welding,after welding penetration compared with TIG welding,TIG welding can reach more than 2.5 times;the tiny A-TIG weld zone with TIG welding,and the preferred growth trend is more obvious;the hardness,the hardness of weld center is A-TIG welding TIG welding slightly lower;in the mechanical properties of A-TIG welding,the tensile strength can reach 95.34% TIG welding,TIG welding and the extension rate is only 87.68% and A-TIG welding,welding plate welding A-TIG welding deformation.In order to obtain the same welding penetration,A-TIG welding can be used welding speed,not only the weld grains and the hardness of welded joint with TIG welding head hardness difference,but the tensile strength of A-TIG welding TIG welding can reach 96.88%,and the extension of TIG welding A-TIG welding rate was only 94.86%.In addition,the deformation of plate,A-TIG welding is relatively small than TIG welding.In order to explore the use of high temperature alloy GH4169 plate welding process in the actual production,this paper adopts the inclinometer measuring deformation of plate after the completion of the welding deformation curves were measured in TIG welding and A-TIG welding.The results show that under the same parameters and the same penetration depth,the deformation of A-TIG welding plate is lower than that of TIG welding plate,which has high practical significance.During the experiment,the arc shape of TIG welding and A-TIG welding were taken respectively.The results showed that the welding arc was obviously reduced after coating the active agent,and the area of the cross section of the arc center was less than 1/3.It can be concluded that after adding the active agent,the welding arc has obvious shrinkage,the current density increases,the arc heat is more concentrated,so as to play a role in increasing the weld penetration.