A Study of Post-current Effect in DC Inverter Resistance Spot Welding

DC 인버터 저항 스폿 용접에서 후전류 효과에 관한 연구

  • Published : 2009.12.15

Abstract

Resistance spot welding has been investigated to apply for manufacturing car bodies because of its high productivity. So quality of resistance spot weld is one of the major concerns for both automobile and aerospace industry. Current design trends in automotive manufacture have shifted emphasis to alternative lightweight materials in order to aid in producing vehicles with higher fuel efficiency and lower down the vehicle emission level for environmental control. There is increasing emphasis to provide lighter cars. Therefore there is an effort to use high strength steels such as HSLA, dual phase, in car body. However there is used in restricted because of difficulty in producing consistently high quality resistance spot welds. In this study, resistance spot welding schedules were developed to achieve acceptable welds with improved static mechanical properties. Improved resistance spot welding schedules were developed using post heating current to reduce the cooling rate, or in-process tempering to reduce the hardness of the weld produced. The effects of resistance spot welding process parameter on hardening fracture mode and static mechanical properties of the joints were determined.

Keywords

References

  1. Rhyu, B. K. and Kang, C. S., 1987, "A Study on the Weldability of Galvannealed Steel in Spot Welding Process," Journal of KWS, Vol. 5, No. 1, pp. 64-72 (in Korean).
  2. Gedeon, S. A., Schrock, D., Lapointe, J., and Eagar, T. W., 1984, "Metallurgical and process Variables Affecting the Resistance Spot Weldability of Galvanized Sheet Steels," SAE Technical Paper 840113.
  3. Gedeon, S. A. and Eager, T. W., 1986, "Resistance Spot Welding of Galvanized Steel : Part I. Material Variations and Process Modifications," Metallurgical Transactions B, 17B, pp. 879-885.
  4. Min, J. K., Oh, Y. K., and Kim, G. S., 1996, "A Study on the Spot Weldability of Automotive Steel Sheets," Journal of KWS, Vol. 14, No. 3, pp. 41-47 (in Korean).
  5. Kim, S. P., Hong, T. M., and Chang, H. S., 1994, "A Study on the Resistance Spot Welding of Aluminium Alloy(I)," Journal of KWS, Vol. 12, No. 4, pp. 127-140 (in Korean).
  6. Son, B. C., Woo, S. Y., J. B. Lee, Y. B. Choi, and H. S. Chang, 1997, "A Study on Resistance Spot Welding of Dissimilar Sheet Metals(Aluminium Alloy- Steel Sheets)," Journal of KWS, Vol. 15, No. 4, pp. 42-62 (in Korean).
  7. Park, J. C., Jung, W. W., and Kang, S. S., 1999, "A Study on the Weldability and the Fatigue Characteristics in Resistance Spot Welding of 5128-O/6061-T6 Dissimilar Aluminium Alloy Sheets," Journal of KWS, Vol. 17, No. 2, pp. 44-52 (in Korean)
  8. Park, H., Kim, T., and Rhee, S., 2003, "Optimization of Welding Parameters for Resistance Spot Welding of TRIP Steel using Response Surface Methodology," Journal of KWS, Vol. 21, No. 2, pp. 76-81 (in Korean).
  9. Kim, E. W. and Eager, T. W., 1998, "Parametric Analysis of Resistance Spot Welding Love Curve," SAE Technical Paper 880278.
  10. Calva, M. and Eager, W., 1990, "Enhancement of the Weldability in Resistance Spot Welding," Sheet Metal Welding Conference IV, Southfield. Mich.
  11. Kim, T. H., Lee, D. O., and Rhee, S., 2005, "Development of Resistance Spot Weldability Estimation Using Lobe Diagram for Steel Plate of Automobiles," Journal of KWS, Vol. 23, No. 4, pp. 369-375 (in Korean).