소입강을 선삭할 때 세라믹공구 인선의 초기파손에 대한 연구 = Early Fracture of Ceramic Tools in Turning of Hardened Steel

다국어 초록 (Multilingual Abstract)

The early fracture is investigated experimentally that occurs in the turning of hardened steel with ceramic tools, and the occurrence condition is clarified. And a method of evaluation is proposed for the early fracture toughness. A turning test is carried out with hardened SUJ2 steel(HRC66) and ceramic tool. The critical cutting speed decided by one-minute criterion is found out, and the influences for the fracture of cutting conditions are clarified. The main findings are as follows:(1) Black ceramic tools show normal wear and long life at lower cutting speed. But they show suddenly early fracture at high speed. (2) The critical cutting speed becomes high according to the decreasing of feed rate, depth of cut and the increasing of corner radius. (3) The critical cutting speed is decided by the maximum undeformed chip thickness. (4) The early fracture is affected by rather the cutting temperature than the cutting force. (5) The early fracture toughness of various ceramics tools is evaluated by the maximum underformed chip thickness and the critical cutting speed. (6) The early fracture is controlled by the coolant.

목차 (Table of Contents)

• 목차
• ABSTRACT
• Ⅰ. 서론
• Ⅱ. 실험방법
• Ⅲ. 실험결과
• 1. 공구수명
• 2. 임계절삭속도의 이송과 모서리반경 관계
• 3. 파손의 발생과 절삭에 대한 최대의 칩두께
• 4. 각종 세라믹공구의 초기파손 특성의 평가
• Ⅳ. 검토
• 1. 소입강의 절삭저항
• 2. 절삭의 칩두께와 절삭온도 및 절삭저항의 관계
• Ⅴ. 절삭액 및 파손에 대한 억제
• Ⅵ. 결론
• 참고문헌