To investigate the precipitation behavior of super duplex stainless steel in its weld by friction stir welding (FSW) at a low welding speed, we carried out microstructural observation and analysis. An intermetallic compound phase, ·, was observed in the heat affected zone (HAZ). The · phase precipitated at the interfaces between ¤-Fe (ferrite) and £ -Fe (austenite) grains 12 mm away from the stir zone (SZ)/HAZ boundary. On the other hand, the Cr2N was observed together with the belt-like £ -Fe grain aggregates in the vicinity of the advancing side (AS) of the SZ. The other intermetallic phase,», was also observed at a triple junction of £ -Fe grains. This demonstrates that the precipitation of the Cr2N and» phases correlates with the transformation of ¤-Fe to £A-Fe (secondary austenite).
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering