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Resistance Spot Welding Process with Pulsed Current Pattern to Improve Joint Strength of Ultra High Strength Steel Sheets
Technical Paper
2015-01-0705
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
We have developed a new resistance spot welding process with “pulsed current pattern”, which consists of short-time high-current post-heating and short-time cooling to improve joint strength of ultra high strength steel (UHSS) sheets with a tensile strength over 980MPa. The high-current post-heating reheats the heat affected zone (HAZ) near the electrodes and that near the sheet-sheet interface rather than the center of the nugget, and this pulsed current pattern utilizes this procedure to improve the toughness of the nugget. In the case of 980MPa grade steel with a 1.6mm thickness, the pulsed current pattern improved cross tension strength (CTS) from 7.2kN to over 10kN and its failure mode from interface failure to plug failure. Tensile shear strength (TSS) showed no drop due to the pulsed current pattern, while the conventional temper pattern welding decreased TSS by about 3kN. 1 time pulsed current achieved CTS above 10kN with plug failure with nugget diameters of 5.2mm to 4.5mm, and 2 time pulsed current expanded the lower limit to 4.4mm. CTS over 10kN and plug failure can be obtained by pulsed current pattern in cases of 980MPa and higher grade steel.
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Taniguchi, K., Matsuda, H., Ikeda, R., and Oi, K., "Resistance Spot Welding Process with Pulsed Current Pattern to Improve Joint Strength of Ultra High Strength Steel Sheets," SAE Technical Paper 2015-01-0705, 2015, https://doi.org/10.4271/2015-01-0705.Also In
References
- Taniguchi , K. , Okita Y. , Ikeda R. Development of Next Generation Resistance Spot Welding Technologies improving the Weld Properties of Advanced High Strength Steel Sheets JFE Technical Report 34 8 13 2014
- Tanaka , J. , Kabasawa , M. , Ono , M. et al. Spot Weldability of High Strength Steel Sheets NKK Technical Report 105 1984
- Beevers , A. , French , E. Post Weld Heat Treatment of Spot Welds in Hardenable Steels British Welding Journal 523 532 Sept. 1962
- Defourny , J. , Bragard , A. Chemistry of the high strength steel sheets for automotive industry and the criteria to define the resistance spot weldability Revue da la Soudure 1 17 24 1984
- Sawanishi , C. , Ogura , T. , Taniguchi K. et al. Mechanical properties and microstructures of resistance spot welded DP980 steel joints using pulsed current pattern Science and Technology of Welding and Joining 19 1 52 58 2014
- Hamatani , H. , Watanabe , F. , Miyazaki , Y. Characterization of cross tension strength in resistance spot welding ultrahigh strength steel sheets Preprints of the national meeting of the Japan Welding.Society 89 44 45 2011
- Mimer , M. , Svensson , L. , Johansson , R. Process adjustments to improve fracture behavior in resistance spot welds of EHSS and UHSS Welding in the world 48 14 18 2004
- Shi , G. , Westgate , S Techniques for improving the weldability of TRIP steel using resistance spot welding Paper for 1 st international conference of the high strength steel 1 13 2005
- Girvin , B. , Peterson , W. , Gould J. Development of Appropriate Spot Welding Practice for Advanced High-Strength Steels AISI/DOE Technology Roadmap Program Final Report No. DEFC36-97ID13554 2004
- Peterson W. , Gould J.E. Development of Spike-tempering diagrams for a range of advanced high-strength sheets Sheet metal welding conference XI 1 25 2004
- Taniguchi , K. , Matsuda H. , Ikeda R. et al. Heat distribution in weld by short-time high-current post-heating and its improving effect on cross tension strength Quarterly journal of Japan welding society 32 3 164 171 2014
- Shiozaki , M. , Kato , T. , Irie , T. et al. Improvement in fatigue strength of spot welded high strength steel joints Tetsu-to-Hagane 68 9 318 323 1982
- Taniguchi , K. , Sadasue , T. , Igi , S. et al. Development of resistance spot welding with pulsed current pattern for high strength steel sheets Preprints of the national meeting of the Japan Welding Society 89 8 9 2011
- Furusako , S. , Watanabe , F. , Murayama G. et al. Current Problems and the Answer Techniques in WeldingTechnique of Auto Bodies - First Part NIPPON STEEL TECHNICAL REPORT 103 MAY 69 75 2013
- Grover , H.J. , Jackson , L.H. Fatigue tests on some spot-welded oints in aluminum alloy sheet materials Welding Journal 26 4 215s 232s 1947
- JWS Bulletin 7 110 117 1982
- Funakawa , Y. , Kabasawa , M. Estimation of cross tension strength of spot weld joint Preprints of the national meeting of the Japan Welding Society 54 256 257 1994