T91 steel containing trace amounts of nitrogen, the role of nitrogen in two aspects. On the one hand from the solid solution strengthening effect, at room temperature under nitrogen solubility in steel small, T91 steel after welding heat affected zone after welding and weld heat treatment process heating Shanghai t91 alloy tube, would have been a solid solution and precipitation processes VN : austenite heating welding heat affected zone has formed as a result of integration into the import t91 alloy tube, VN nitrogen content increases, the degree of supersaturation at room temperature after which the organization raised and a tiny VN in the subsequent post-weld heat treatment precipitation, which increases the stability of the organization, to improve the enduring strength values ??of the heat affected zone. On the other hand, T91 steel also contains a small amount of A1, with the formation of nitrogen can A1N, A1N in a lot more than 1 100 ℃ was dissolved in the matrix t91, again precipitated at lower temperatures, can play a better dispersion strengthening effect. The high pressure seamless steel pipe is different t91, high-pressure steel pipe is mainly used in high-temperature high-pressure pipeline plant power plant boiler factory high temperature, high pressure resistance, 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 _ Katherine source seamless steel pipe (certified) _ Tanggu District 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.