Numerical simulation of 2219 aluminum alloy flat under the condition of subsection welding or no subsection welding was analyzed by the double ellipsoidal heat source model. The result shows that the residual tensile ...Numerical simulation of 2219 aluminum alloy flat under the condition of subsection welding or no subsection welding was analyzed by the double ellipsoidal heat source model. The result shows that the residual tensile stress of subsection welding appears in the weld and nearby areas while the peak value appears in the weld. The subsection welding can greatly increase the low stress area in the weld. Moreover, the contrast of stress between the subsection welding and no subsection welding shows that if the welding sequence, namely that the double ends of the weld are welded first and then the middle part is welded, is adopted in the subsection welding, the peak value of residual tensile stress can be greatly decreased.展开更多
On basis of the subsection welding and the local heating s reasonable technological parameters obtained by plane experiment,the welding residual stress field of some Francis turbine runner is regulated and controlled....On basis of the subsection welding and the local heating s reasonable technological parameters obtained by plane experiment,the welding residual stress field of some Francis turbine runner is regulated and controlled.For the experimental plane with a thickness of 16 mm,the effect of subsection welding on decreasing welding residual stress of the prior welding section is obvious when the distance is less than 50 mm away from the end of latter welding section.For the local heating,the best position,where the effect on decreasing the welding residual stress of plane is best,is 60 mm or so away from the edge of heating area.The experimental results of runner show that the subsection welding can make the residual compressive stress engender in the blade dangerous area while the stress value is greatly influenced by the length of the welding section of blade outlet.The local heating can further decrease the value of residual stress near blade outlet,while the local heating processed after heat treatment is better than that processed before heat treatment.展开更多
文摘Numerical simulation of 2219 aluminum alloy flat under the condition of subsection welding or no subsection welding was analyzed by the double ellipsoidal heat source model. The result shows that the residual tensile stress of subsection welding appears in the weld and nearby areas while the peak value appears in the weld. The subsection welding can greatly increase the low stress area in the weld. Moreover, the contrast of stress between the subsection welding and no subsection welding shows that if the welding sequence, namely that the double ends of the weld are welded first and then the middle part is welded, is adopted in the subsection welding, the peak value of residual tensile stress can be greatly decreased.
文摘On basis of the subsection welding and the local heating s reasonable technological parameters obtained by plane experiment,the welding residual stress field of some Francis turbine runner is regulated and controlled.For the experimental plane with a thickness of 16 mm,the effect of subsection welding on decreasing welding residual stress of the prior welding section is obvious when the distance is less than 50 mm away from the end of latter welding section.For the local heating,the best position,where the effect on decreasing the welding residual stress of plane is best,is 60 mm or so away from the edge of heating area.The experimental results of runner show that the subsection welding can make the residual compressive stress engender in the blade dangerous area while the stress value is greatly influenced by the length of the welding section of blade outlet.The local heating can further decrease the value of residual stress near blade outlet,while the local heating processed after heat treatment is better than that processed before heat treatment.
