The Wear Failure Analysis And Controling Of Wheel Balancer Warm Plastic Forming Die

Usually, in metal’s warm and hot plastic forming, the die’s working environment isvery bad.Under the conditions of high temperature, overloading, strong impact and so on,the life of the warm or hot extrusion dies are relatively short. The main failure forms of thedies are wear failure, fracture failure, and plastic deformation. Combining with one autoparts manufacturing company’s actual production in Shanghai,the wear failure of the wheelbalancer upsetting extrusion dies have been analyzed, and the die material is H13hot-workdie steel.The research present situation of the warm plastic forming die’s wear failure analysisand die’s wear failure type and the wear mechanism in common have been discussed inthis thesis. This thesis also give a brief introduction in the application of CAE analysis inmetal plastic forming and the research status of H13die steel’s surface modification.According to the wear failure die’s macro-appearance,the high temperature friction andwear experiment and the die surface test results by XRD, it has been determined that thedie’s wear mechanism are the interaction of the adhesive wear,fatigue wear, oxidationthermal wear. The adhesive wear and fatigue wear plays a leading role. The alloy elementscontent, die hardness, microstructure, carbides size and distribution of the failure die havebeen analyzed.Deducing from the die material analysis,the processing and heat treatmentprocess in the die’s manufacture are generally reasonable. The influence of the die workingconditions for die wear have been analyzed. The initial temperature of the die, thetemperature of billet, the die hardness and the running speed of the upper die have beenanalyzed and the parameters have been optimized by DEFORM-3D software. The die’shardness changes by laser surface hardening. The die materials have been quenched bylaser with different laser parameters.The microhardness, hardening depth andmicrostructure have been observed and analyzed. The high thermal wear resistance alsohas been tested, and compared with the untreated materials. It finds that the grainsrefinement or super refinement in the hardening layer.The depth of the hardening layer is as deep as0.8mm or so, and the average hardness of the hardening layer increases by25%.The wear resistance also increases about three times.It is more appropriate that the laserscanning lap-amount is selected20%. According to the experiment results, the appropriatelaser surface hardening parameters is choosed.The die where is easily worn and measured have been quenched by laser, and on thebasis of the die’s working parameters which have been optimized, we produced a batch ofparts in practice. According to the comparison of the dies’ wear pattern with the sameproduction, it finds that the wear resistance of the die quenched by laser have beenimproved obviously.