Welding thermal cycle of grain heat-affected zone of welded joints have a significant impact grew t91, especially close to the heating temperature is the highest fusion zone. When the cooling rate is small import t91 alloy tube, in the weld heat affected zone will appear coarse massive ferrite and carbides organization t91 steel, the plastic steel decreased; the cooling rate is large, due to the generation of coarse Markov body tissue, but also make plastic welded joints decreased. The high-pressure pipe is different, mainly used in high-pressure steel pipe high temperature high pressure power station boiler factory plant resistance to high temperature, resistance to high pressure, supercritical boiler tubes above the main pipe, product quality requirements are very stringent. 20G boiler tubes, 15CrMoG boiler tubes, 12CrMoVG boiler tubes t91 T22 boiler tube boiler tubes. All of my steel products meet the technical certification authority of the national certification examination department of the American Association of steel, British NVB product quality certification, Italy ADS pipeline industry standard certification. 20G steel, 15CrMoG steel, 12Cr1MovG 16Mo3 steel pipe steel P91, P22 steel, T91 steel, T22 steel, Wb36 steel products Gold won the national quality inspection. t91 alloy tube 51X3.5_ Katherine source steel (certified) _t91 provided by source Pipe Co., Ltd. Liaocheng trillion. Liaocheng Katherine source Pipe Co., Ltd. (www.lczygg.com) Shandong Liaocheng, steel leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Katherine source leader in steel with the staff warmly welcome all inquiries negotiations to create Katherine source steel a better future.