Browse > Article
http://dx.doi.org/10.5781/KWJS.2013.31.1.43

Analysis of Microstructure for Resistance Spot Welded TRIP Steels using Atomic Force Microscope  

Choi, Chul Young (School of Materials Science and Engineering, Pusan National University)
Ji, ChangWook (School of Materials Science and Engineering, Pusan National University)
Nam, Dae-Geun (Korea Institute of Industrial Technology (KITECH))
Jang, Jaeho (School of Materials Science and Engineering, Pusan National University)
Kim, Soon Kook (Dept. of Advanced Material Engineering, Dong-Eui University)
Park, Yeong-Do (Dept. of Advanced Material Engineering, Dong-Eui University)
Publication Information
Journal of Welding and Joining / v.31, no.1, 2013 , pp. 43-50 More about this Journal
Abstract
The spot welds of Transformation Induced Plasticity (TRIP) steels are prone to interfacial failure and narrow welding current range. Hard microstructures in weld metal and heat affected zone arenormally considered as one of the main reason to accelerate the interfacial failure mode. There fore, detailed observation of weld microstructure for TRIP steels should be made to ensure better weld quality. However, it is difficult to characterize the microstructure, which has similar color, size, and shape using the optical or electron microscopy. The atomic force microscope (AFM) can help to analyze microstructure by using different energy levels for different surface roughness. In this study, the microstructures of resistance spot welds for AHSS are analyzed by using AFM with measuring the differences in average surface roughness. It has been possible to identify the different phases and their topographic characteristics and to study their morphology using atomic force microscopy in resistance spot weld TRIP steels. The systematic topographic study for each region of weldments confirmed the presence of different microstructures with height of 350nm for martensite, 250nm for bainite, and 150nm for ferrite, respectively.
Keywords
Resistance spot welding; TRIP steels; Atomic force microscope; Scanning electron microscopy; optical microscopy;
Citations & Related Records
연도 인용수 순위
  • Reference
1 S. S. Park, Y. M. Choi, D. G. Nam, Y. S. Kim, J. H. Yu and Y. D. Park, Journal of KWJS, 26-6 (2008), 625
2 S. S. Park, Y. D. Park, K. H. Kim, Y. M. Choi, Y. M. Rhym and N. H. Kang, Journal of KWJS. 26-2 (2008), 177
3 K. C. Kim, J. H. Cha and H. S. Park, Journal of Materials Research. 14-4 (2004), 239
4 D. J. Radakovic and M. Tumuluru, American Welding Journal. 87(2008), 96
5 C. Y. Choi, I. B. Kim, Y. D. Kim and Y. D. Park, Kor. J. Met. Mater. 50-2 (2012), 136
6 C. Y. Choi, J. K. Kim, J. K. Hong, J. T. Yeom and Y. D. Park, J. P. Journal of KPMI. 18-1 (2011), 64
7 C. H. Lee, K. H. Lee, J. H. Yoon and Y. E. Shin, Journal. KWJS. 26-1 (2008), 56
8 S. M. An, T. K. Yim, K. S. Lee, J. H. Kim, E. Y. Kim and K. W. Park, Kor. J. Met. Mater. 49-4 (2011)
9 K. C. Chung, Y. K. Kim and C. J. Choi, Kor. J. Met. Mater. 48-4 (2010), 320
10 C. Y. Choi, I. B. Kim, Y. D. Kim and Y. D. Park, Kor. J. Met. Mater. 50-2 (2012), 136   DOI
11 T. H. Kim, H. S. Park, Y. S. Lee, S. H. Rhee, Proc. J. KSAE. 2 (2003), 1239
12 B. Girvin, W. Peterson and J. Gould, American Iron and Steel Institute. 27 (2007), A10
13 F. S. Lepera, Metallography. 12 (1979), 263   DOI   ScienceOn
14 M. Tumuluru, American Welding Journal. 86-6 (2007), 161s
15 T. R. Yanez, Y. Houbaert, A. Mertens, Materials Characterization. 47 (2001), 93   DOI   ScienceOn