Effect of Heat Input on Post-Weld Microstructure and Mechanical Properties in FSW X-65

摘要

Post-weld microstructure and Charpy impact properties in FSW API 5L grade X-65 were examined. The objective of this work is to establish correlations between weld heat input, Charpy impact toughness, and weld microstructures. Three different weld heat inputs were investigated, and impact toughness was tested at three locations across the weld. Charpy impact toughness along the weld centerline exhibits a strong correlation with weld heat input. Impact properties at the advancing side of the weld nugget and in the HAZ showed no correlation with weld heat input. However, these did show a strong correlation with average hardness along the notch locations. This paper describes these correlations and other factor that influence the postweld impact properties.