Motors are becoming an environment-friendly alternative around the world. Environment-friendly automobile parts in particular require high quality and productivity. To improve these requirements, we studied a manufacturing technology called mold technology. A disadvantage of mold mass-production is a fatigue failure after a relatively large amount of friction and pressure on the processed products. Eventually, this leads to problems of repair costs, production stoppages, and quality defects. To address these problems, a surface- treatment technique is often used to improve mechanical properties by coating the mold surfaces. In this study, we measured the abrasion on (1) Tungsten Carbide punch and (2) TiAlCrN coated punch during the mold mass-production of the cold-rolled steel plate motor core made with SCP-1 (thickness of 1.0mm). With the extracted data, it is proved that using TiAlCrN coated punch affects the reduction of the inner diameter damage of the product. Furthermore, our goal is to reduce repair cost and improve productivity by predicting the lifespan of the mold and identifying the time expectancy of grinding, maintenance, and repair of the mold.

In this study, Equivalent fracture strain and Fracture energy were evaluated with the small punch test(SP test) for friction stir welded(FSW) Al6061-T6 sheets. With the three rotation speeds and the three feeding rate, The nine different conditions of FSW were prepared for the SP test. The SP test specimens were manufactured and tested on the advancing side, center, and retreating side to the tool rotation direction. From the SP test data, the equivalent fracture strain and the fracture energy were analyzed. The high value of equivalent fracture strain was attained form tool rotational speed 900RPM and feeding rate 330mm/min. It is found that its characteristic is about 14% higher than the value of condition 1100RPM-330mm/min that have the lowest value. The high value of fracture energy was obtained from the tool rotation speed 900RPM and feeding rate 330mm/min. The lowest fracture energy, which from 1000RPM-300mm/min, was approximately 16% difference to the highest value.

A press which has a 20 percent share in machine tools is one of the production facilities. Recently hydraulic press is used to reinforce competitiveness of the manufacturing industry. The press by using metal powder makes products without additional process while conventional processing machine makes products after removing unnecessary parts. In this way, large quantity of products can be produced in a short time. Researches to manufacture products by the press have been proceeding after 1970. In this study, structure and displacement analysis for shape parameters for punch used as the component for hydraulic press was investigated and structural stability was identified based on the results.

A press which has a 20 percent share in machine tools is one of the production facilities. The press has been used to make a hole or to bend metal plates. However, recently hydraulic press is used to reinforce competitiveness of the manufacturing industry. The press by using metal powder makes products without additional process while conventional processing machine makes products after removing unnecessary parts. In this way, large quantity of products can be produced in a short time. Researches to manufacture products by the press have been proceeding after 1970. In this study, structure and displacement analysis for punch used as the component for hydraulic press was investigated and structural stability was identified based on the results

The hydrogen embrittlement of high strength steel for automobiles was evaluated by small punch (SP) test. The test specimens were fabricated to be 5 series, having various chemical compositions according to the processes of heat treatment and working. Hydrogen charging was electrochemically conducted for each specimen with varying of current density and charging time. It was shown that the SP energy and the maximum load decreased with increasing hydrogen charging time in every specimen. SEM investigation results for the hydrogen containing samples showed that the fracture behavior was a mixed fracture mode having 50% dimples and 50% cleavages. However, the fracture mode of specimens with charging hydrogen changed gradually to the brittle fracture mode, compared to the mode of other materials. All sizes and numbers of dimples decreased with increasing hydrogen charging time. These results indicate that hydrogen embrittlement is the major cause of fracture for high strength steels for automobiles; also, it is shown that the small punch test is a valuable test method for hydrogen embrittlement of high strength sheet steels for automobiles.

The reduction of setup time is very important in a lot production system. A punch press is a typical system of lot production. This paper describes a case study to reduce setup time of a punch press manufacturing system. Especially, this case study reduce

사용중인 중화학 설비의 재료물성의 경년열화적 특성을 평가하기 위하여 기존 실험법의 인장시험편이나 충격시험편을 채취하기는 실제적으로 불가능하다. 인장강도등 인장특성과 비교한 결과 인장강도, 연신율, 항복강도, 종탄성계수와 소형펀치실험의 각 특성과 선형적 관계를 얻을 수 있었다. 또한 경년열화도를 평가하는 두구인 파면천이온도(FATT)와 비교하기 위하여 저온 소형펀치실험을 실시한 결과 충격실험을 통하여 구한 FATT온도와 소형펀치실험의 천이온도 ( Tsp )와 일정한 관계가 있음이 밝혀져 사용재의 열화도를 평가할 수 있다.