Browse > Article
http://dx.doi.org/10.5781/KWJS.2013.31.6.96

Effect of Hot-stamping on Microstructures and Tensile Properties of Al-Si Coated Boron Steel Welds with Laser Source  

Oh, Myeong-Hwan (National Core Research Center, Pusan National University)
Kong, Jong-Pan (Dept. of Material Science and Engineering, Pusan National University)
Kwon, Min-Suck (Hyundai Hysco Co., Ltd. Light weight and Pipe R&D Team)
Kang, Chung-Yun (National Core Research Center, Pusan National University)
Publication Information
Journal of Welding and Joining / v.31, no.6, 2013 , pp. 96-106 More about this Journal
Abstract
In this study, the effect of laser source($CO_2$ and Nd:YAG) on the microstructure and tensile properties of laser welded Al-Si coated boron steel(1.2mmt) was investigated with before and after hot-stamping. In case of as welds condition, fracture occurred in base metal unrelated to the laser source. It could be explained that tensile strength of fusion zone composed of martensite and bainite is higher than that of base metal that contains a lot of ferrite despite dilution of Al and Si from coating layer to fusion zone. In case of hot-stamping condition, the fracture occurred in fusion zone irrelevant to laser source and the tensile strength was lower than hot stamped base metal. In the $CO_2$ laser welds, $Fe_3$(Al,Si) formed near the bond line was transformed into ferrite during hot-stamping. Therefore tensile strength of bond line is lower than that of base metal and center of fusion zone and the fracture occurred in the bond line. On the other hand, in the Nd:YAG laser welds, the higher concentration of Al formed the ferrite in the fusion zone during hot-stamping treatment. Also, the thickness of centerline was thinner than that of base metal. Therefore, it is considered that fracture occurred in centerline of fusion zone due to effect of concentration stress, and it leaded to a lower tensile strength and elongation.
Keywords
Al-Si coated layer; $CO_2$ laser; Nd:YAG laser; Hot-stamping; Microstructure; Tensile properties;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 T. Mega, and H. Kawabe : JFE Tech. Report, 4, (2004), 38
2 H. Karbasian and AE. Tekkaya : J. Mater. Process. Technol., 210 (2010), 2103-2118   DOI   ScienceOn
3 Francesca Borsetto, Stefania Bruschi : Operations, Key Engineering Materials, 410-411 (2009), 289-296   DOI
4 C.-H. Kim, and Y.-D. Park : J. Achiev Mater Manuf Eng, 39 (2010), 79-86
5 C. Kim, M. J. Kang, Y. D. Park : Procedia Engineering, 10 (2011), 2226-2231   DOI   ScienceOn
6 R. Vierstraete and Q. Yin : Industrial Laser Solutions., 25-2 (2010)
7 Byung Hun Jung and Chung Yun Kang : Korean Journal of Metals and Materials, 50-6 (2012), 455- 462 (in Korean)   DOI
8 Yong Gyu An and Chung Yun Kang : Jurnal of KWJS, 29-1 (2011), 90-98 (In Korean)
9 Jong-Do Kim and Ki-Chol Kim : Jurnal of KWJS, 25-4 (2007), 72-78 (in Korean)
10 N. Saunders and J.-Ph. Schille : JOM, 55-12 (2003), 60-65   DOI   ScienceOn
11 Rosenthal Daniel : Welding journal, 20-5 (1941), 220-234
12 Rosenthal Daniel : ASME, 48 (1946), 848-866
13 S.P. Gupta : Materials Characterization 49-4 (2003), 269-291
14 Maitra, T., and S. P. Gupta., : Materials Characterization, 49-4 (2003), 293-311
15 Narayanan. L., and J. E. Gruzleski., : Metallurgical and Materials Transactions A, 25-8 (1994), 1761-1773   DOI
16 RATHOD M. J., KUTSUNA. M. : Welding Journal - New York-, 83-1 (2004), 16-26
17 D. K. MUKHOPADHYAY : Metallurgical and Materials transactions A, 26A (2004), 1939-1959