Metallography, Microstructure, and Analysis

, Volume 6, Issue 6, pp 489–501 | Cite as

Friction Stir Welding of EH46 Steel Grade at Dwell Stage: Microstructure Evolution

Technical Article


This work aims to understand the effect of changes in friction stir welding (FSW) process parameters on the resulting microstructure specifically the effect of the plunge depth and tool rotational speed, during the “dwell” period on the resulting microstructure. A series of (FSW) of 14.8-mm-thick EH46 steel plate using a hybrid polycrystalline boron nitride FSW tool with spindle speeds of 120 and 200 revolutions per minute have been produced with increasing plunge depths from 0.1 to 0.7 mm. Thermocouples embedded around the top surface of each plunge case were used to measure the peak temperature during the process. The plunge depths were measured using the infinite focus microscopy, and the microstructure of all the heat affected regions was investigated extensively by scanning electron microscopy. It was found that phase transformation is sensitive to the variation on plunge depth. Small increase in plunge depth caused a significant change in the microstructure. Increasing tool rotational speed was also found to cause a significant difference in the microstructure.


EH46 steel Friction stir welding Plunge depth Microstructure 



The authors would like to thank the Ministry of higher education Iraq for funding this project, thanks for TWI/Yorkshire Company for providing samples, data and advice.


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© Springer Science+Business Media, LLC and ASM International 2017

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Al-Furat Al-Awsat Technical UniversityKufaIraq
  2. 2.MERISheffield Hallam UniversitySheffieldUK
  3. 3.Coventry UniversityCoventryUK

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