Numerical Simulation And Experimental Study On Weld Shape Of Electron Beam Welding Of High Carbon And High Chromium Stainless Steel

Electronic beam welding is better than traditional welding methods,with less soldering defects,more centralized,and small thermal influence zones,and electron beam welding process parameters have an important impact on weld geometry and joint tissue performance.High carbon high chromium stainless steel is widely used in machinery,automobile and other fields,but due to high carbon content,the weldability is poor.Electron beam welding is one of the best methods to improve the weldability and quality of high carbon and high chromium stainless steel.In this paper,numerical simulation and experiment were used to study the weld morphology of 440C stainless steel electron beam welding joint with 5mm thickness,various process parameters（electron beam flow,welding speed,scanning function）The influence of the weld geometry,the welding process parameters of welds are selected for the pre-welding process 440C stainless steel,observes the characteristics of their tissue and performance,and obtain the following conclusions:（1）The increase in the electron beam current and welding speed can improve the deep ratio of the weld,and the shape of the welds obtained from different scanners have a large difference,and the sawtooth wave weld is funny,and the circular wave weld is wedge-shaped.With the increase of the magnitude of the scan function,the deep ratio of the weld is reduced,and he deep ratio of the weld increases with the frequency of the scan function increases.（2）The results show that the surface energyθis related to the weld forming.When the saw tooth scanning function is used,the weld joint will collapse when the surface energyθ≥1.58×10^-2J·mm^-3;when the surface energy 0.65×10^-2J·mm^-3≤θ≤1.4×10^-2J·mm^-3,the weld joint can be penetrated without collapse;when the surface energyθ≤0.62×10^-2J·mm^-3,the weld joint cannot be penetrated.When circular scanning function is used,whenθ≥1.98×10^-2J·mm^-3,the welded joint will collapse;when 0.78×10^-2J·mm^-3≤θ≤1.29×10^-2J·mm^-3,the welded joint can be penetrated without collapse;whenθ≤0.73×10^-2J·mm^-3,the welded joint cannot be penetrated.（3）The annealing state and the tempered thermal influence area are composed of martensite and carbide.Due to the mass transfer,martensite transition,some carbide dissolution,so the carbide ratio in the annealed weld is more.The dendride of the annealing weld is grown,inhibits the martensite phase change,so the dendritic crystal ratio is much stronger,and the grain size is large,the residual austenite is more than the conditioned state.（4）Both annealed and quenched-tempered welded joints have higher hardness in HAZ,and the hardness in quenched-tempered HAZ is higher than that in annealed HAZ.The tensile and bending fracture positions are in the heat affected zone.The tensile strength,elongation and bending strength of the annealed and quenched-tempered joints are lower than those of the base metal.