DOI QR코드

DOI QR Code

Al-Si 용융 도금된 보론강의 Yb:YAG 디스크 레이저 용접부의 미세조직과 인장성질에 미치는 도금두께의 영향

Effect of Coating Thickness on Microstructures and Tensile Properties in Yb:YAG Disk Laser Welds of Al-Si Coated Boron Steel

  • Cao, Wei-Ye (Dept. of Material Science and Engineering, Pusan National University) ;
  • Kong, Jong-Pan (Dept. of Material Science and Engineering, Pusan National University) ;
  • Ahn, Yong-Nam (Advanced Welding & Joining Department, Korea Institute of Industrial Technology) ;
  • Kim, Cheol-Hee (Advanced Welding & Joining Department, Korea Institute of Industrial Technology) ;
  • Kang, Chung-Yun (Dept. of Material Science and Engineering, Pusan National University)
  • 투고 : 2013.05.18
  • 심사 : 2013.06.27
  • 발행 : 2013.06.30

초록

In this study, the effect of coating thickness($20{\mu}m$ and $30{\mu}m$) on microstructure and tensile properties in Yb:YAG disk laser welds of Al-Si-coated boron steel (1.2mmt) was investigated. In the case of as welds, the quantity of ferrite was found to be higher in base metal than that in HAZ (Heat Affected Zone) and fusion zone, indicating, fracture occurrs in base metal, and the fracture position is unrelated to the coating thickness. Furthermore, yield strength, tensile strength of base metal and welded specimens showed similar behavior whereas elongation was decreased. On the other hand, base metal and HAZ showed existence of martensite after heat treatment, the fusion zone indicated the presence of full ferrite or austenite and ferrite during heat treatment ($900^{\circ}C$, 5min), After water cooling, austenite was transformed to martensite, and the quantity of ferrite in fusion zone was higher as compared with in base metal, resulting in sharply decrease of yield strength, tensile strength and elongation, which leads to fracture occured at fusion zone. In particular, results showed that because the concentration of Al was higher in 30um coating layer specimen than that of 20um coating specimen, after heat treatment, producing a higher quantity of ferrite was higher after heat treatment in the fusion zone; howevers, it leads to a lower tensile property.

키워드

참고문헌

  1. Senuma, Takehide : Physical Metallurgy of Modern High Strength Steel Sheets, ISIJ Int, 41 (2001), 520 https://doi.org/10.2355/isijinternational.41.520
  2. T. Mega, K. Hasegawa, and H. Kawabe, : Ultra High-Strength Steel Sheets for Bodies, Reinforcement Parts, and Seat Frame Parts of Automobile-.Ultra High-Strength Steel Sheets Leading to Great Improvement in Crash-worthiness-, JFE Tech. Report, 4 (2004), 38
  3. L. Vaissiere, J. P. Laurent, and A. Reihardt : Development of pre-coated boron steel for applications on PSA peugeotcitroën and RENAULT bodies in white, Int. body eng. conf. & exhibition, Paris, French, (2002), 909
  4. L. G. Aranda, P. Ravier, and Y. Chstel : Hot stamping of quenchable steels : material data and process simulations, IDDRG, Conf. Proc., (2003), 155-164
  5. R. Kolleck, D. Steinhoefer, J. A. Feindt, and P. Bruneau : Manufacturing methods for safety and structural body parts for lightweight body design, IDDRG, Conf. Proc., (2004), 167-173
  6. H. S. Liu, Z. W. Xing, J. Bao, and B. Y. Song : Investigation of the hot-stamping process for advanced high-strength steel sheet by numerical simulation, J. Mater. Eng. & Perform, 19 (2010), 325-334 https://doi.org/10.1007/s11665-009-9510-y
  7. M. Geiger, M. Merklein, and C. Hoff : Basic investigations on the hot stamping steel 22MnB5, Adv. Mater. Res., 6 (2005), 795-804
  8. Kolleck. R., Veit. R., Merklein. M., Lechler. J., and Geiger. M. : Investigation on induction heating for hot stamping of boron alloyed steels, CIRP Annals-Manufacturing Technology, 58 (2009), 275-278 https://doi.org/10.1016/j.cirp.2009.03.090
  9. H. Karbasian and AE. Tekkaya : A review on hot stamping, 210, J. Mater. Process. Technol., 210 (2010), 2103-2118 https://doi.org/10.1016/j.jmatprotec.2010.07.019
  10. Francesca Borsetto, Andrea Ghiotti, Stefania Bruschi : Investigation of the High Strength Steel Al-Si Coating during Hot Stamping, Operations, Key Engineering Materials, 410-411 (2009), 289-296 https://doi.org/10.4028/www.scientific.net/KEM.410-411.289
  11. W. Ehling, L. Cretteur, A. Pic, R. Vierstraete, and Q. Yin : Development of a Laser Decoating Process for Fully Functional Al-Si Coated Press Hardened Steel Laser Welded Blank Solutions, 5th Int. WLT, Conf. Proc. (2009), 409
  12. Vierstraete, R. Ehling, W. Pinard, F. Cretteur, L. Pic, A. Yin, Q : Laser ablation for hardening laser welded steel blanks, Industrial Laser Solutions for Manufacturing, 25 (2010), 2-6
  13. Byung Hun Jung, Jong Pan Kong, Chung Yun Kang : Effect of hot-stamping Heat Treatment on Microstructure and Hardness in TWB Laser Joints of Al-Si coated Boron Steel and Zn-Coated DP Steel, Korean J. met. mater., 50-3 (2012), 224-232
  14. Y. Kim, K. Y. Park, B. Y. Lee : A Study on Laser Weldability of Al-Si Coated 22MnB5 Steel for TWB Hot Stamping, KWJS, 31 (2013), 32 (in Korean) https://doi.org/10.5781/KWJS.2013.31.2.30
  15. M. Potesser, T. Schoeber H, Antrekowisch and, J Brucker : The Characterization of The Inter-metallic Fe-Al Layer of Steel-Aluminum weldings, TMS The Minerals, Metals & Materials society, (2006), 167-176
  16. D. K. MUKHOPADHYAY : Structural Elolutionin Mechanically Alloyed AI-Fe Powders, Metallurgical and Materials transactions A, 26A (1994), 1939-1959
  17. Y. G. An, C. Y Kang, Y. S. Kim, C. H. Kim: Microstructures and Hardness of DISK Laser Welds in Al-Si Coated Boron Steel and Zn Coated DP Steel, KWJS, 29 (2011), 93-94 (in Korean) https://doi.org/10.5781/KWJS.2011.29.1.090

피인용 문헌

  1. The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (I) - Laser Weldability of Al-Si Coated Boron Steel Used for Hot Stamping Process - vol.38, pp.12, 2014, https://doi.org/10.3795/KSME-A.2014.38.12.1367
  2. Effect of keyhole mode on weld shape and mechanical properties of thin sheets of Al-Si coated 22MnB5 steel vol.30, pp.4, 2018, https://doi.org/10.2351/1.5052155