SSAW steel pipe temperature control
Update:
2016-11-29 View(s):
2446 Keywords :SSAW steel pipe
SSAW steel pipe welding temperature is mainly affected by the high-frequency eddy thermal power, high-frequency eddy current heating power is mainly affected by the frequency, power and thermal eddy current excitation frequency is proportional to the square; but also by the current excitation frequency excitation voltage, current and capacitance, inductance.
When the lack of heat input, the weld edge is heated up to a temperature of less than welding, metal structure remains solid, the formation of incomplete fusion or penetration; insufficient when the input heat, weld edge over the heated soldering temperature, resulting in burnt or droplet, so that the weld formation Caverns.
Welding multilayer of spiral welded steel pipe also considers inter-layer temperature to control the cooling rate near the weld zone. Interface temperature and preheat temperature are generally similar. Under avoid overheating premise near seam zone between the higher layer prevents cold crack temperature during multi-pass welding. After the heat treatment and welding heat pipeline construction is not usually performed after heat treatment after welding and heat treatment. But for construction in the alpine region, when the inter-preheat and interface temperature control is difficult to play a greater role, it is necessary to take certain joints after welding heat and heat treatment measures.
