Investigations Into the Microstructure–Toughness Relation in High Frequency Induction Welded Pipes

In the present paper, investigations performed on ArcelorMittal X65 linepipe steel in order to understand the effects of high frequency induction (HFI) welding process and in-line post-weld heat treatment on weld properties are described. The factors that potentially can affect weld toughness, such as microstructure, grain size, precipitates, hardness, inclusions, and texture, are evaluated and discussed systematically in order to correlate weld microstructure with toughness of the HFI welded pipes.