| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
New Frontiers in Physical Metallurgy of Steels
|
| Presentation Title |
Austenite Decomposition in the Coarse Grain Heat Affected Zone of X80 Line Pipe Steel |
| Author(s) |
Sabyasachi Roy, Matthias Militzer, Warren J. Poole |
| On-Site Speaker (Planned) |
Sabyasachi Roy |
| Abstract Scope |
Welding of steels results in microstructure changes in the heat affected zone (HAZ). The coarse grain HAZ (CGHAZ) experience temperature close to the melting point and is regarded as a potential region of failure. In the present work, continuous cooling austenite decomposition has been studied for three different line pipe steels subjected to conditions relevant for the CGHAZ. An increase in carbon content from 0.035wt% to 0.061wt% leads to a decrease in transformation temperature of up to 50°C, whereas a chromium increase from 0.023wt% to 0.24wt% resulted in approximately 10°C decrease in transformation temperatures. Microstructure characterization and hardness testing confirmed that lower transformation temperatures are associated with finer bainitic microstructures and higher hardness values. Based on the experimental results a phenomenological model has been proposed to predict the transformation kinetics, microstructure and hardness as a function of cooling rate and steel chemistry in terms of C and Cr content. |