What is the welding process of 12Cr1MoV steel pipe?

12Cr1MoV steel pipe is one of the widely used pearlitic heat-resistant steels in China. It is mainly used in the manufacture of boiler overheat pipe, header and main steam pipe whose tube wall temperature is less than 580℃.

In the manufacturing process of 12t/h double-drum transversal boiler furnace, the steam outlet temperature of the boiler is 450℃, the maximum working pressure is 3.8MPa, according to the design drawing requirements of the use of 12Cr1MoV steel pipe as the super-heater header tube, to meet the requirements of the product use.
12Cr1MoV steel tubes are low alloy heat-resistant steels, which have high Cr content and have high thermal strength and endurance strength at 500-550℃.

According to the chemical composition of 12Cr1MoV steel pipe, the content of carbon and alloying elements in 12Cr1MoV steel pipe is more, and the quenching sensitivity is greater, and the quenching micro-structure is easy to appear in the weld and heat affected zone.

When the joint is rigid and the stress is large, it is easy to produce cold crack. Because the superheated header is a pressure element working at a higher temperature, necessary technological measures should be taken during welding to ensure that the welding joints have enough thermal strength to ensure the safe operation of the superheated header.