Key Points in Overall Post-Weld Heat Treatment Quality Control
Post-weld heat treatment aims to eliminate residual stresses and enhance low-temperature toughness in pressure vessels.
Post-weld heat treatment aims to eliminate residual stresses and enhance low-temperature toughness in pressure vessels. The temperature, time, and heating/cooling rates must be carefully considered.
4.1 Determining Soaking Temperature Conditions
Considerations include avoiding adverse effects on high-strength low-temperature steels and preventing tempering brittleness.
4.2 Determining Soaking Time Conditions
Balancing soaking time is critical for stress relaxation without undesirable consequences like grain coarsening.
4.3 Determining Heating and Cooling Speeds
Adjusting heating and cooling speeds based on steel composition and thickness helps avoid new temperature-induced stresses.
4.4 Determining Entry and Exit Temperatures
Entry and exit temperatures should be below 400℃, considering the shape, size, and on-site conditions to prevent additional stresses.
