Microstructure and mechanical properties of friction-stir welded St52 steel joints

Küçükömeroğlu T., Aktarer S. M., İpekoğlu G., Çam G.

INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS, vol.25, no.12, pp.1457-1464, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 25 Issue: 12
  • Publication Date: 2018
  • Doi Number: 10.1007/s12613-018-1700-x
  • Journal Name: INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1457-1464
  • Keywords: friction-stir welding, St52 steel, microstructure, mechanical properties, LASER, WELDABILITY, ALLOYS
  • Recep Tayyip Erdoğan University Affiliated: Yes

Abstract

The aim of this work is to investigate the mechanical properties and microstructures of friction-stir welded (FSWed) St52 structural steel joints. In this study, St52 steel plates with a thickness of 4 mm were butt-welded by friction-stir welding (FSW) using a tungsten carbide tool having a conical pin. The microstructure of the welded zone consists of equiaxed fine ferrite, grain boundary ferrite, Widmanstatten ferrite, and aggregates of ferrite + cementite. The microhardness measurements showed that the hardness of the welded zone was significantly higher than that of the base metal. The FSWed St52 joint exhibited a significant strength overmatching in the weld region and a strength performance similar to or slightly higher than that of the base plate.