Continuous Cooling Transformation Temperatures and Microstructures of Niobium Bearing Microalloyed Steels

Abstract:

Effects of niobium content and cooling rate on ferrite and bainite start temperatures (Ar3, Bs) and microstructural features have been studied in niobium bearing ultralow carbon microalloyed steels. The Ar3 and Bs temperatures decrease as niobium content or cooling rate is increased. The dependence of Ar3 on cooling rate is greater than that of Bs in all niobium contents. The bainitic ferrite laths become longer and narrower with increasing niobium content and cooling rate, and niobium also shows a tendency to decrease polygonal ferrite grain size.

• Periodical: Materials Science Forum (Volumes 475-479)
• Pages: 65-68
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.475-479.65
• Online since: January 2005
• Authors: Young-Kook Lee, Jin-Myung Hong, Chong Sool Choi, Jae Kon Lee
• Keywords: Bainite Start Temperatures, Cooling Rate, Ferrite Start Temperatures, Microalloyed Steel, Microstructure, Niobium Content

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