Most of automobile steering parts are manufactured through the multi-stage cold forging process using round-bar drawn materials. The same process is applied to the ball stud parts of the outer ball joint, and various research activities are being carried out to reduce the extreme manufacturing cost in order to survive in the limitless competition. In this paper, we present a quantitative prediction method for the limiting life of the die as a method for cost reduction in the multi-stage cold forging process. The load on the die was minimized by distributing the forming load based on process optimization through finite element analysis. In addition, based on the quantitative prediction algorithm of the limiting life of the die, the application of the split die and the optimization of the phosphate treatment of the material surface are presented as a conclusion as a method to improve the limiting life of the die.

Heat treatment of metals is an necessary process for obtaining properties required for metals. However, the heat treatment sector is labor intensive enough to be classified as an unwanted sector. In particular, in the case of quenching during the heat treatment, in order to select the defective product due to the collision caused by the collision between the products when the product is dropped in the oil tank during the quenching process, the labor is not concentrated on the heat treatment as the main process, It is a fact that it is put in. In this paper, in order to solve the labor - intensive nature, this paper designed and tested prototype products for the selection of defective products during the heat treatment process of the ball stud. The ball stud inspection device is divided into two parts, a ball stud supply device and an inspection device, and describes the concept design and prototype production contents. The performance of the prototype was evaluated by examining 1000 samples with 5 items. The manufactured ball stud inspection system will contribute to the relaxation of the avoidance phenomenon of the heat treatment industry and contribute to the efficiency and competitiveness of the work.