Sturdy On Microstructure And Properties Of Repaired Layer Of Remanufactured HT250 Matrix

Remanufacturing technology as a new type of green manufacturing technology gradua llybecome an important part of the manufacturing industry because of its unique advantag es such as high quality,efficient,and energy-savingand.It also plays a vital role in balan cing the world economic development and alleviating the pressure on resources and envir onment.Surface damage is the main failure modes of parts,how to choose the appropriate surface repair techniques plays a decisive role on the repaired parts performance.Advanced surface engineering technology as the core of remanufacturing technology has been widely used inrepairing the parts.Because of economical,convenient,accurate and small heat affected zoneadvantages,cold welding technology regularly used in the repairing process.How to ensure the remediation efficiency,reduce remediation deficiency,heat affected zone and welding residual stress,achieved good interfacial bonding strength of the cole welding method,has become a bottleneck problem witch restricting it widely used in the remanufacturing industry.This paper mainly focus on this problems,studying the mechanism,microstructure,residual stress and other key points of the remanufacturing technology of HT250 gray cast iron which widely used in the engine cylinder body of automobile manufacturing.In this paper,the author studies the organization performance and the binding conditi ons at the interface of the matrix and repair layer of the defects in HT250 gray cast iron which repaired by using the sub laser instantaneous melting technology.(1)Studying the welding temperature field and stress field of the repair process of the sub laser instantan eous melting technology by using the SYSWELD software.Simulation results show that t he temperature of the center line is changed with the moving of the heat source,and the stress and deformation are mainly concentrated in the center line of the specimen repair.(2)Analysing the microstructure,elements distribution at the interface of the matrix and repair layer and phase analysis of combined interface of the repaired sample.Revealing the internal organization changes,element diffusion and metallurgical bonding mechanism of the repaired specimen by using the sub laser instantaneous melting technology.(3)Stu ding the residual stress at the bonding interface of the matrix and repair layer,revealing the law of the stress-strain of the repaired samples.(4)Analysising the method of selecti ng process parameters of the remanufacturing process of the HT250 gray cast iron.The r esults show that the enter power P and signal repair time t have a great impact on the p erformance of the repaired sample.The select of the p and t must ensure the full meltin g of the repaired materials,otherwise the defects such as pores and cracks will appear.The optimal remanufactured HT250 matrix conditions are input power of 2800 W,processi ng time of 0.65 s,frequency of 1 hz,and gas flow of 1.5 L/min.This topic through the above Systematic study can provide sub laser instantaneous melting technology in autom obile manufacturing industry in the application mechanism and the optimal process param eters,this research can be used as a reference for the sub laser instantaneous melting tec hnology used in automobile manufacturing field.