Effect of heat input on the microstructure of the friction stir weldedTRIP steel joints

  • H.G. Tehrani Moghadam Department of of Metallurgy, IUST Tehran, Iran
  • Hamid Reza Jafarian Department of of Metallurgy, IUST Tehran, Iran
Keywords: FSW; TRIP steel; Microstructure; electron backscattered diffraction.

Abstract

The high-Ni TRIP steel plates were friction stir welded at rotational and traverse speeds of 600 rpm-100 mm-min- 1 and 950 rpm-50 mm-min-1, respectively for high and low heat input conditions. The optical microscopy, X-Ray diffraction (XRD), orientation image microscopy (OIM), and tensile test were employed for characterization of the joints. The results showed that friction stir welding replaced the large grains of the base metal with fine and equiaxed grains by continuous dynamic recrystallization (CDRX). In addition, friction stir welding lead to stabilization of the austenite. The lower heat input condition caused finer grain sizes. Using lower heat inputs resulted in more retained austenite by means of both work hardening and finer grain size mechanisms

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Published
2019-08-09
How to Cite
Tehrani Moghadam, H., and H. Reza Jafarian. “Effect of Heat Input on the Microstructure of the Friction Stir WeldedTRIP Steel Joints”. ZANCO Journal of Pure and Applied Sciences, Vol. 31, no. s3, Aug. 2019, pp. 324-8, doi:10.21271/ZJPAS.31.s3.45.