Evaluating HAZ Microstructures and Properties of Welded Microalloyed TMCP Steels
Joel Pepin, MSc student in Materials Engineering
Supervisor - Dr. Douglas Ivey, Dr. Hani Henein
As current oil and gas wells continue to be drilled, subsequent projects are being proposed in locations with increasingly harsh conditions. Pipelines for such projects must endure low temperatures, high pressures, and cyclical strain-loading, while remaining economically viable.
Microalloying is used in conjunction with thermo-mechanical controlled processing (TCMP) to produce steel sheets possessing an attractive combination of microstructures and dispersions of precipitates. The resulting reductions in alloying costs, and increase in strength and toughness, make such steels ideal for high-pressure pipeline applications.
During pipe fabrication, the steel sheets are spiral-welded, which changes the microstructure in the heat-affected zone (HAZ) running parallel to the weld. A literature review was performed to determine the changes to microstructure in the HAZ, and the resulting changes to mechanical properties. The review proposes options to reduce the detrimental effects on HAZ microstructure, while listing potential difficulties determining the corresponding changes to mechanical properties. |
.gif){kind=spacer}
