Characterization and microstructural evolution model of a Nb ferrite-bainite steel

• Main Author: Gerami, Sepehr
• Language: English
• Published: University of British Columbia 2010
• Online Access: http://hdl.handle.net/2429/28753

Complete microstructural evolution models for dual phase ferrite-bainite micro-alloy steels do not yet exist despite their widespread use. An attempt is made here to make a contribution towards development of a unified model. Transformation behaviour in a niobium bearing line-pipe steel is investigated. Grain growth and recrystallization studies are performed, and the results used to design continuous cooling transformation tests to study the effects of prior austenite grain size, cooling rate, retained strain, and niobium dissolution on transformation behaviour in the steel. Existing modelling techniques are then applied to the experimental data in order to predict ferrite and bainite transformation start temperatures and transformation kinetics.