Formability Analysis And Process Design Of Heat Resistant Steel Automobile Exhaust Pipe

Exhaust pipe is an important part of automobile parts,which is mainly used to reduce vibration and noise and prolong the life of exhaust muffler system.At present,the problem of using automobile exhaust pipe is the defect of noise elimination effect.The engine is damaged due to long-term bad exhaust.The high temperature and water vapor generated during exhaust are easy to cause oxidation failure of exhaust pipe.In the stamping process,the inner cone shell of exhaust pipe is easy to be broken and wrinkled due to its complex structure and large drawing depth.The rationality of the structure of the inner cone shell of the exhaust pipe is very important,which will directly affect the muffler effect and exhaust function,and indirectly affect the power of the engine.Therefore,the development and application of heat resistant steel in exhaust pipe and the optimization of the inner cone shell structure of exhaust pipe become the focus of automobile industry.This project took the heat resistant steel exhaust pipe inner cone shell as the research object,aimed to analyze and studied the forming performance and process design of the exhaust pipe inner cone shell:(1)The composition of the heat resistant steel sheet was detected,and the properties of the sheet were analyzed by the proportion of each element.Then the hardness and FLC curve of the material were studied by hardness detection and tensile test,so as to analyze the influence of the sheet itself on the formability of the inner cone shell.(2)This paper analyzed the technology of heat resistant steel inner cone shell,analyzed the product manufacture of the inner cone shell,and calculated the blanking force of each separation process,the drawing force and pressing force of the drawing process.According to the nominal pressure,the corresponding stamping equipment was selected,and then the process design of the inner cone shell was carried out,finally the stamping process of each process was analyzed.(3)The forming process simulation model of heat resistant steel inner cone shell was established.The finite element analysis of the inner cone shell was carried out by using DYNAFORM simulation software.The wrinkling,cracking and other forming properties of the inner cone shell were studied through the thinning rate and FLD curve.The drawing process was optimized through the feedback of simulation results.Finally,the stamping die of the inner cone shell was verified,to ensure the reasonable stamping process and good formability of the inner cone shell.