[Chemical Equipment Powerful Equipment] 371—X70 grade 40.5mm high-strength thick-walled pipeline steel plate for deep sea use

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This post was last edited by Yuyu in the Desert on 2022-6-21 19:11. Comply with the Safety Production Law! Be the first responsible person! ----------------------------------------------- The past ten years have been an era of great development for China's chemical industry. The emergence of many new processes, new products, and new equipment has also led to a great development in my country's chemical equipment, which has also promoted the rapid development of the petrochemical industry. Here we have collected and sorted out some of the achievements and breakthroughs made by my country's equipment companies in the large-scale and localization of equipment. Welcome everyone to share, discuss, and exchange, cheer for Made in China, and cheer for chemical equipment! ------------------------------------------------------ In order to adapt to the development trend of high strength, large wall thickness and small diameter thickness ratio of deep sea pipelines, Baoji Petroleum Steel Pipe Company, together with domestic steel mills, took the lead in developing X70 steel grade, 40.5 mm wall thickness, high strength and large wall thickness pipeline steel plates for deep sea use. The chemical composition and rolling process determine the metallographic structure, and the metallographic structure and pipe making process determine the performance of the steel pipe. Therefore, the design of the chemical composition and metallographic structure is very important. The requirements for anti-deformation performance of submarine pipelines require that a dual-phase structure, that is, a soft phase and a hard phase, should be selected during structural design. The soft phase structure is used to ensure the anti-deformation performance of the material, while the hard phase structure can provide the necessary strength, that is, the ratio of soft phase ferrite and hard phase acicular ferrite or bainite can be reasonably controlled to achieve a lower yield ratio. Based on the above organizational design ideas and in accordance with the composition design concept of low carbon bainitic steel, low C, Nb, Ti micro-alloying and composite addition of Ni, Mo and other alloying elements are used in the composition design. Through a reasonable TMCP process, the micro-alloying elements can give full play to the effects of refining austenite grains and precipitation strengthening. S, P, N, O and other inclusions in the steel are strictly controlled during the steelmaking process. While ensuring the excellent low-temperature toughness and good welding performance of the steel plate, the dual-phase structure control of the plate structure is achieved. Combining the characteristics of Anshan Iron and Steel's 5500 mm wide plate production line, by controlling the starting cooling temperature, cooling speed and end cooling temperature of the steel plate, an X70 steel grade deep-sea pipeline steel plate with a wall thickness of 40.5 mm was successfully developed.