Banded microstructure in a low-alloyed eutectoid steel. Issue 4 (4th March 2019)

• Record Type: Journal Article
• Authors: Kannan, Rangasayee; Wang, Yiyu; Li, Leijun
• Is Part Of: Materials science and technology. Volume 35:Issue 4(2019)
• Page Start: 394
• Page End: 402
• Publication Date: 2019-03-04
• Subjects: Hypereutectoid steel -- heavy section -- bainite -- segregation -- fracture; Materials science -- Periodicals; Microstructure -- Periodicals; Metallurgy -- Periodicals; 620.1105
• DOI: 10.1080/02670836.2019.1567030
• Languages: English
• ISSNs: 0267-0836

Abstract

ABSTRACT: The possible influence of banded microstructure on the fracture performance of a high-carbon steel is investigated using electron microscopy and X-ray diffraction techniques. The banded microstructure was found to be alternating layers of bainite and tempered martensite/retained austenite. Transformation of bainite was promoted by a combined effect of segregation of alloying elements, non-uniform thermal gradient across the steel, and the insufficient austenitisation. The transformation of bainite along the prior austenite grain boundaries (PAGBs) introduces a non-uniform strain distribution at bainite/martensite interface and a higher stress concentration, which may eventually lead to the failure of the heavy section in a brittle intergranular manner. Results provide insights to the importance of understanding the bainitic transformation in such eutectoid steel systems.