Study On Welding Repair And Remanufacturing Of Aluminum Profile Extrusion Die

This article is for the repair of aluminum profile extrusion die.The industry used to use the traditional GTAW to remanufacturing repair the die.However,GTAW needs large heat input and faces complex repair process in industrial applications,such as preheating before welding and welding heat preservation.To explore another simple way to achieve respectable performance instead of using GTAW,the research turns to the cold welding repair technology and CMT repair welding technology.The research explore the influence of the two mentioned techniques on H13 die steel(after heat treatment),respectively.Specifically,different process parameters are used to conduct the analysis of microstructure,test the mechanical properties,and do the matrix and weld performance analysis of friction for specific experiments.The final experimental results show that:(1)After the cold welding repair,the repair layer is tightly bonded to the substrate,achieving the good forming effect and with no pores,inclusions and cracks.In addition,the cold welding cause little influence to the matrix,since the distribution range of welding residual stress is very small and the main residual stress is the transverse residual stress,which makes the substrate materials have little plastic deformation.(2)The heat input of the cold welding and CMT welding is significantly reduced when compared with GTAW.They have little effect on the microstructure and properties of the repaired area.Specifically,the hardness is decreased from the weld heat affected zone to the substrate by setting different process parameters,and the maximum hardness is achieved in the heat affected zone.The thermal effect of CMT is slightly larger than the cold welding,but it is much less than that of GTAW.Both cold welding and CMT welding technology can significantly reduce the heat input,thus can be better used in mold repair.(3)After cold welding repair,the weld seam and substrate friction of H13 steel face the situation of abrasive wear,adhesive wear and oxidative wear.The aluminum will penetrate into the matrix,the weld surface of the hot crack,will further accelerate the crack growth under high temperature extrusion,which accelerates the substrate surface with the weld surface wear and makes the service life become short.