2012 年 78 巻 790 号 p. 2340-2349
The amount of usage of the high-strength steel in the sheet metal forming section of the car, which is effective for the light weight, is increasing in order to satisfy the fuel saving and the safety. It is required not only the durability but also the brief manufacturing lead time for making the stamping die tool. This paper proposes a technique to fabricate the trimming die tool which is a part of the sheet metal stamping section by using the “molten metal lamination”, which is realized by adding the welding function to the NC machine. In addition, a welding material that can has high hardness by the subzero treatment, which is cooled with the dry ice after the accumulated molten metal part is finished by milling process, is developed. As a result, it is shown that the molten metal lamination using welding with the high quality becomes possible on the NC machine, and a simple stamping die tool structure and the reduced lead time can be realized. Moreover, the trimming die tool with the subzero treated weld material shows as well or better wear resistance compared with the SKD11 in one million shot endurance test.