중공형 STS304 스테인리스 강재 부품 제작을 위한 다단 플러그 인발 공정의 패스 스케줄 설계

다국어 초록 (Multilingual Abstract)

The plug drawing process, one of the cold tube drawing processes, uses a pair of drawing dies and a plug to simultaneously reduce the outside diameter and thickness of the initial tube while increasing its length. The use of plugs enables relatively high dimensional accuracy and excellent straightness of the drawn tube to be secured compared to the tube sinking process. In this study, materials and parts manufactured through the plug drawing process are mainly used in transportation machinery and robotics industrial equipment as housings for servo motors. Housing materials and parts for servo motors are facing problems such as noise and reduced product life due to dimensional errors in the cutting and assembly processes after drawing processing, and the importance of dimensional accuracy and roundness for the outer diameter and thickness of the drawn tube is increasing. Therefore, this study aims to develop a theoretical design method for stable multi-pass plug drawing processing of housing materials and parts for servo motors. A pass schedule design method for a multi-pass plug drawing process is proposed based on a strain control model that considers the dimensional change of the tube and a flow stress prediction model using the A. Geleji formula. To verify the proposed pass schedule, elastic-plastic finite element analysis and field experiments were performed for a 3 pass plug drawing process. The initial outer diameter and thickness dimensions of the hollow STS304 stainless steel used for verification were 44.5 mm and 1.1 mm, respectively. The drawing load for each pass, tube dimensions, and fracture during the drawing process were analyzed through elastic-plastic finite element analysis. Subsequently, through field experiments, we successfully manufactured a precision housing part with a final outer diameter of 39.9 mm and a thickness of 0.67 mm, which met the required specifications for housing materials and parts for servo motors. Through this, it was confirmed that the pass schedule design method of the multi-pass plug drawing process proposed in this study can be applied to the manufacturing of high-precision hollow steel materials and parts. Keywords : Multi-pass plug drawing process, STS304 stainless steel pipe, Pass schedule design, Advanced strain control model, Finite element analysis

목차 (Table of Contents)

• List of Tables ⅱ
• List of Figures ⅲ
• Nomenclature ⅳ
• Abstract ⅴ
• 1. 서론 1
• 1.1 연구 배경 1
• 1.2 연구 동향 4
• 1.3 연구 목적 및 범위 7
• 2. 다단 플러그 인발 공정의 패스 스케줄 설계 9
• 2.1 냉간 튜브 인발 공정의 개요 9
• 2.2 개선된 변형률 제어 모델 개발 10
• 2.3 유동응력 예측 모델을 이용한 강재 파단 예측 13
• 2.4 3 패스 플러그 인발 공정의 패스 스케줄 설계안 17
• 3. 3 패스 플러그 인발 공정의 유한요소해석 19
• 3.1 유한요소해석 조건 19
• 3.2 유한요소해석 결과 21
• 4. 3 패스 플러그 인발 가공 실험 29
• 4.1 3 패스 플러그 인발 가공 조건 및 방법 29
• 4.2 3 패스 플러그 인발 가공 실험의 결과 32
• 5. 결론 40
• 6. 참고 문헌 42
• 7. 국문 초록 45
• 8. 감사의 글 47