Acta Metallurgica Sinica (English Letters) ›› 2023, Vol. 36 ›› Issue (5): 789-802.DOI: 10.1007/s40195-023-01521-y

Previous Articles     Next Articles

EBSD Characterization of Microstructure and Micro-texture in a Friction Stir-Welded DP600 Steel

H. Ashrafi1(), M. Shamanian2, M. Sanayei3, F. Farhadi4, J.A. Szpunar3   

  1. 1Faculty of Chemical and Materials Engineering, Shahrood University of Technology, Shahrood, 3619995161, Iran
    2Department of Materials Engineering, Isfahan University of Technology, Isfahan, 8415683111, Iran
    3Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9, Canada
    4Department of Materials Science and Engineering, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
  • Received:2022-10-19 Revised:2022-12-10 Accepted:2022-12-15 Online:2023-01-12 Published:2023-01-12
  • Contact: H. Ashrafi

Abstract:

The microstructure and micro-texture in different areas of a friction stir (FS)-welded DP600 steel were investigated by means of electron backscatter diffraction. The volume fraction of martensite and non-polygonal ferrite was evaluated based on the image quality (IQ) parameter. Analysis of grain boundaries revealed that the fraction of sub-grain boundaries as well as that of low-angle grain boundaries in the heat-affected zone (HAZ) and stir zone (SZ) was more than doubled compared to those in the DP600 steel base metal (BM). The micro-texture examination of the BM showed strong {112} < 110 > and {111} < 112 > components with an intensity 4.6 times of that random texture. The texture showed a memory effect in the HAZ, with a reduced overall intensity. Within the SZ, D1, D2 and E shear texture components together with a cube component were developed. Formation of these texture components of ferrite were attributed to the transformation of B and R texture components of prior austenite, which are evidences of continuous dynamic recrystallization mechanism in the SZ of the friction stir-welded DP600 steel.

Key words: Dual phase steel, Friction stir welding, Micro-texture, Image quality