DOI QR코드

DOI QR Code

Optimization of Friction Welding for Motor Vehicle Safety Belts: Part 1-Mechanical Properties and Microstructure

수송차량 안전벨트용 모터축재의 마찰용접 최적화(1) - 기계적 특성 및 조직

  • Received : 2012.02.03
  • Accepted : 2012.02.13
  • Published : 2012.02.29

Abstract

Dissimilar friction welds were produced using 15-mm diameter solid bars of chrome molybdenum steel (KS SCM440) and carbon steel (KS SM20C) to investigate their mechanical properties. The main friction welding parameters were selected to ensure good quality welds on the basis of visual examination, tensile tests, Vickers hardness surveys of the bond area and HAZ, and macro-structure investigations. The specimens were tested as-welded and post-weld heat treated (PWHT). The tensile strength of the friction welded steel bars was increased to 100% of the SM20C base metal under the condition of a heating time of more than four seconds. Optimal welding conditions were n = 2,000 (rpm), HP = 60 (MPa), UP = 100 (MPa), HT = 5 (s),and UT = 5 (s), when the total upset length was 7.8 (mm). The hardness distribution peak of the friction welded joints could be eliminated using PWHT. The two different kinds of materials were strongly mixed to show a well-combined structure of macro-particles, with no molten material, particle growth, or defects.

Keywords

Friction welding;Post weld heat treatment (PWHT);As-welded;Base metal (BM);Heat affected zone (HAZ);Weld interface (WI);Welding condition

References

  1. 공유식, 윤성필, 김선진 (2010). "자동차 후진기어용 축재(SM45CSF45) 의 이종마찰용접 특성", 대한기계학회논문집 A권, 제34권, 제1호, pp 85-90.
  2. 기계공작학편집위원회 (2001). 신편기계공작학, 산업도서, pp 89-91.
  3. 대한용접학회 (1998). 용접․접합편람, pp 663-664.
  4. 마찰압접협회 (1979).마찰압접, 코로나, 제1장, pp 1-2.
  5. (사) 일본열처리기술협회 (2009). 입문.금속재료의 조직과 성질, 타이가사.
  6. 오세규, 김부안, 김선진, 남상훈 (1988). "S45C와 SCM4의 마찰 용접 및 피로특성에 관한 연구", 한국해양공학회지, 제2권, 제2호, pp 312-321.
  7. 이배섭, 공유식, 김선진 (2005). "해양차량 쇽업소버용 강재의 이종 마찰용접과 AE 평가", 한국해양공학회지, 제19권, 제1호, pp 44-48.
  8. 일본철강협회 (2011). 강의 열처리, 기전연구사, pp 46-48.
  9. AWS (1981). "Welding Handbook-Vol1, Fundamentals of Welding", 7th edition, Vol1, pp 153-220.
  10. Cho, H.S. and Suh, S.J. (1997). "Friction Welding of Inconel 713C and SCM440", Journal of KWS, Vol 15, No 6, pp 78-84.
  11. Jeong, H.S. and Shinoda, T. (1997). "Fundamental and Basic Application of Friction Welding", Journal of KWS, Vol 15, No 6, pp 1-12.
  12. Kang, S.B. and Min, T.K. (1988). "A Study on the Friction Weldability of Carbon Steel(S45C) to Aluminum Alloy (A6063)", Journal of KWS, Vol 16, No 2, pp 153-220.
  13. Kong, Y.S. and Kim, S.J. (2006). "Mechanical Properties of Dissimilar Friction Welded Steel Bars in Relation to Post Weld Heat Treatment", Trans. of the KSME(A), Vol 30, No 4, pp 402-408.
  14. Oh, S.K., Kong, Y.S., Yoo, I.J. and Kim, I.S. (2000). "Creep Life Prediction for Dissimilar Friction-Welded-Joints of Turbine Impeller Heat Resisting Steels and AE Evaluation (1)-FRW and AE Evaluation", Proc. of International Offshore and Polar Eng. Conf., ISOPE, Seattle, USA, pp 203-207.

Acknowledgement

Supported by : 한국연구재단