Grain refinement in coarse-grained heat-affected zone of Al–Ti–Mg complex deoxidised steel. (2nd January 2019)

• Record Type: Journal Article
• Authors: Liu, Yu; Wan, Xiangliang; Li, Guangqiang; Wang, Yong; Zheng, Wan; Hou, Yanhui
• Is Part Of: Science and technology of welding & joining. Volume 24:Number 1(2019)
• Page Start: 43
• Page End: 51
• Publication Date: 2019-01-02
• Subjects: Deoxidation -- inclusions -- precipitates -- grain size -- CGHAZ -- acicular ferrite; Welding -- Periodicals; Joints (Engineering) -- Periodicals; Surfaces (Technology) -- Periodicals; 671.52
• DOI: 10.1080/13621718.2018.1476804
• Languages: English
• ISSNs: 1743-2936

Abstract

ABSTRACT: The particles and microstructure characteristics of coarse-grained heat-affected zone (CGHAZ) in Al–Ti–Mg killed steels with different Al contents were investigated. The results show that inclusion in high Al steel consists of Al–Mg oxide surrounded with a layer of MnS. However, inclusion in low Al steel is Al–Ti–Mg oxide covered with a layer of MnS, effectively promoting the formation of acicular ferrite. The precipitates of both steels are (Ti, Nb)N, the finer and more dispersed inclusions and precipitates in low Al steel can effectively inhibit austenite grain growth by grain boundary pinning during the thermal cycle. The fine-grained microstructure is obtained in CGHAZ of the low Al steel due to the pinning effect of finer particles and the high density of acicular ferrite.