Partial austenitisation and TBF steel composed of ferrite, bainitic ferrite, and austenite


ERİŞİR E., BİLİR O. G. , Sozer Y. E. , ARARAT Ö., Davut K.

MATERIALS SCIENCE AND TECHNOLOGY, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2022
  • Doi Number: 10.1080/02670836.2022.2102289
  • Journal Name: MATERIALS SCIENCE AND TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: TBF steels, partial austenitisation, phase transformations, microstructural characterisation, mechanical properties, MECHANICAL-PROPERTIES, STRENGTH, MICROSTRUCTURE, MARTENSITE, FORMABILITY, DUCTILITY, EBSD, NB, ALUMINUM
  • Kocaeli University Affiliated: Yes

Abstract

A TRIP-aided bainitic-ferritic (TBF) steel with a chemical composition of Fe-0.19C-1.7Mn-1.09Si-0.51Al-0.05Nb (wt-%) was partially austenitised from a hot-rolled martensitic initial microstructure. After the hot rolling, the martensitic specimens were reheated to different intercritical temperatures and then austempered at 350 degrees C. Thus, the effect of the initial microstructure of TBF steel on intercritical austenite formation during partial austenitisation was studied. The microstructures were investigated by scanning electron microscopy and electron backscatter diffraction (EBSD), and the tensile properties were tested. Microstructural observations revealed that a final microstructure of fine ferrite, bainitic ferrite, and retained austenite can be obtained. The steel partial austenitised at 770 degrees C showed a good combination of ultimate tensile strength and total elongation.