L52350 Microstructure and Properties of Simulated HAZ - Welding Solutions for X100 Line Pipe

A Gleeble thermal simulator was used to simulate HAZ microstructures and evaluate phase transformations associated with single and multipass regions of pipeline girth welds. The first step was to establish realistic thermal cycles (histories) for a wide range of welding process/procedure conditions, including GMAW-P welding. In this investigation the transformation behaviour of simulated grain coarsened heat-affected zone (GCHAZ) regions formed in three X100 pipe steels and a modern X80 pipe steel of similar composition were established by dilatometry. In addition, the notch toughness was evaluated using different simulated GCHAZ and intercritcally reheated (ICRGCHAZ) regions in order to establish the transition behaviour compared with the respective pipe steels.

This work was cofunded via PHMSA Project DTPH56-07-000005.