Pipe fitting dimensions: Φ610×110mm pipe；Material grade: 12Cr1MoVG

Welding preheating process requirement: 200°C; post-welding heat treatment requirement: 730°C.

According to the process specifications, four temperature measurement points are established, with controlled temperature <390°C, a heating rate of 80–100°C/h, a holding period of 330 minutes at 730±10°C, and a cooling rate of 80–100°C/h to 390°C.