Journal of the Korean Society for Heat Treatment (열처리공학회지)

The Korean Society for Heat Treatment (한국열처리공학회)
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Effects of Alloy Additions and Annealing Parameters on Microstructure in Cold-Rolled Ultra Low Carbon Steels

극저탄소 냉연강판에서 합금원소 및 어닐링조건이 미세조직에 미치는 영향

  • Jeong, Woo Chang (School of Mechanical and Automotive Engineering, Catholic University of Daegu)
  • 정우창 (대구가톨릭대학교 기계자동차공학부)
  • Received : 2004.01.26
  • Published : 2004.03.30
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Abstract

Effects of the annealing parameters on the formation of ferrites transformed at low temperatures were studied in cold-rolled ultra low carbon steels with niobium and/or chromium. Niobium and chromium were found to be effective in the formation of the low temperature transformation ferrites. The low temperature transformation ferrites more easily formed when both higher annealing temperature and longer annealing time, allowing substitutional alloying elements to distribute between phases, are in combination with faster cooling rate. It was found from EBSD study that the additions of niobium or chromium resulted in the increase in the numbers of high angle grain boundaries and the decrease in those of the low angle grain boundaries in the microstructures. Both granular bainitic ferrite and bainitic ferrite were characterized by the not clearly etched grain boundaries in light microscopy because of the low angle grain boundaries.

Keywords

Acknowledgement

Supported by : 대구가톨릭대학교

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