Advertisement

Production Engineering

, Volume 5, Issue 6, pp 629–639 | Cite as

Numerical and experimental analysis of electric conductive heating for micro warm coining of stainless steel

  • K. Zhao
  • B. Wietbrock
  • G. Hirt
Production Process

Abstract

The aim of this study was to investigate the electric conductive heating of stainless steel, which is the initial step in the research of micro warm coining of high strength metals. This paper presents the numerical and experimental analysis of the electric conductive heating under variation of heating time, electric current and heating atmosphere. The material used was stainless steel X5CrNiMo17-12-2 (1.4401). The geometry of the samples was 100 × 50 mm2 with an initial thickness of 1 mm. A 3D coupled thermal-electrical model in Abaqus/Standard was used to help analyzing the heating process. The results of FEM simulation show that using 1,600 A electric current within 5 s conductive heating could give a uniform temperature distribution area of 20 mm × 20 mm as the micro warm coining zone at a temperature around 900°C. The simulation was confirmed by experimental results showing a similar temperature distribution, heating rate and cooling rate. Heating under vacuum increased the maximum temperature slightly as compared to heating under argon or air during the electric conductive heating. Closed die micro warm coining with integrated electric conductive heating of stainless steel has been successfully realized.

Keywords

Electric conductive heating 3D coupled thermal-electrical numerical analysis Stainless steel Micro warm coining 

Notes

Acknowledgments

The authors gratefully acknowledge the financial support by Deutsche Forschungsgemeinschaft (DFG).

References

  1. 1.
    Ike H (2003) Surface deformation vs bulk plastic deformation—a key for microscopic control of surfaces in metal forming. J Mater Process Technol 138:205–255CrossRefGoogle Scholar
  2. 2.
    Rattay B (2003) Bestimmung der Einflußgrößen Herstellung von Mikrokanalstrukturen beim Prägen metallischer Bleche. Dissertation, University of SaarlandesGoogle Scholar
  3. 3.
    Thome M, Hirt G (2005) Metal flow and die filling in coining of microstructures with and without flash. Adv Mater Res 68:631–638CrossRefGoogle Scholar
  4. 4.
    Kim GY, Koc M, Ni J (2006) Investigation on coining of microfeatures using pure copper. In: ASME International conference on manufacturing science and engineering. Ypsilanti, MIGoogle Scholar
  5. 5.
    Neugebauer R, Schubert A, Kadner J, Burkhardt T (1999) High precision embossing of microparts. Adv Technol Plast 2:19–24Google Scholar
  6. 6.
    Wulfsberg JP, Hilpert SE, Ostendorf A (2003) Sapphire tools for Laserassisted microforming. In: Proceedings of 4th International symposium on laser precision microfabrication SPIE 5063, pp 172–176Google Scholar
  7. 7.
    Holtkamp J, Bayer A, Groche P (2005) Mikroumformen mit lokaler Bauteilerwärmung durch Laserstrahlung in transparenten Werkzeugen. Abschlussbericht zum DFG-Schwerpunktprogramm 1074 Erweiterung der Formgebungsgrenzen bei Umformprozessen. pp 111–118Google Scholar
  8. 8.
    Karunasena WG, Greene GW, Chen NNS (1978) Direct resistance heating characteristics of rectangular sheet blanks. IEEE Trans Ind Appl IA 14:282–288CrossRefGoogle Scholar
  9. 9.
    Mori K, Maki S, Tanaka Y (2005) Warm and hot stamping of ultra high tensile strength steel sheets using resistance heating. CIRP Ann 54:209–212CrossRefGoogle Scholar
  10. 10.
    Geiger M, Merklein M, Vogt U (2009) Aluminum tailored heat treated blanks. Prod Eng Res Devel 3:401–410. doi: 10.1007/s11740-009-0179-8 CrossRefGoogle Scholar
  11. 11.
    Li YH, Sellars CM (1998) Comparative investigations of interfacial heat transfer behaviour during hot forging and rolling of steel with oxide scale formation. J Mater Process Technol 80–81:282–286CrossRefGoogle Scholar
  12. 12.
    Zhao K, Wietbrock B, Hirt G (2011) Micro warm coining of stainless steel sheets using electric conductive heating. Key Eng Mater 473:991–998. doi: 10.4028/www.scientific.net/KEM.473.991 CrossRefGoogle Scholar
  13. 13.
  14. 14.
    Cole-Parmer technical library. http://www.coleparmer.com/techinfo/techinfo.asp. Accessed 28 July 2009
  15. 15.
    Stankus SV, Savchenko IV, Baginskii AV, Verba OI, Prokopev AM, Khairulin RA (2008) Thermal conductivity and thermal diffusivity coefficients of 12Kh18N10T stainless steel in a wide temperature range. High Temp 46:731–733CrossRefGoogle Scholar
  16. 16.
    Cezairliyan A, Miiller AP (1980) Thermophysical measurement on low carbon 304 stainless steel above 1,400 K by a transient technique. Int J Thermophys 1:84–95Google Scholar
  17. 17.
    Sensor Therm technical data sheet. http://www.sensortherm.de/en/digital-pyrometer-overview. Accessed 11 June 2010
  18. 18.
    Coupled thermal-electrical analysis. In: Abaqus user’s manual 6.9, chapter 2.12.1Google Scholar

Copyright information

© German Academic Society for Production Engineering (WGP) 2011

Authors and Affiliations

  1. 1.Institute of Metal FormingRWTH Aachen UniversityAachenGermany

Personalised recommendations