High strength X90 pipeline steel and production method thereof

Abstract

The invention provides a high-strength X90 pipeline steel which is characterized by containing the following chemical components (in weight percentage): 0.030 percent to 0.090 percent of C, 1.55 percent to 2.50 percent of Mn, less than or equal to 0.6 percent of Si, less than or equal to 0.0030 percent of S, less than or equal to 0.015 percent of P, 0.015 percent to 0.120 percent of Nb, 0.005 percent to 0.030 percent of Ti, less than or equal to 0.120 percent of V, less than or equal to 0.060 percent of Alt, less than 0.60 percent of Mo, less than 1.2 percent of Cu, less than 1.5 percent of Ni, less than 1.2 percent of Cr, less than 0.0015 percent of B, less than or equal to 0.01 percent of Ca, 0.003 percent to 0.010 percent of N, 0.001 percent to 0.006 percent of O, and the rest are Fe and inevitable impurities. The invention also provides a production method of the pipeline steel. The pipeline steel has high strength, high impact toughness, good welding performance and crack arrest capability, and plays an obvious role in reducing the construction cost of transportation pipelines.

Description

technical field [0001] The invention belongs to the field of iron and steel materials, and more specifically, the invention relates to X90 pipeline steel. Background technique [0002] In recent years, the changes in the energy structure and the increase in energy demand have greatly promoted the development of long-distance transmission pipelines. In order to improve transmission efficiency and reduce project investment, it has become a trend to develop steel for long-distance oil and gas transmission pipelines to high-grade steel. At present, the highest steel grade in the pipeline steel standards used by various countries in the world is only X80 (yield strength greater than or equal to 555MPa). In order to meet the development of long-distance oil and gas transportation in the future, higher strength grades are required, such as X90 (yield strength grade greater than or equal to 621MPa). ), X100 (yield strength grade greater than or equal to 690MPa) and X120 (yield stre...

AI Technical Summary

Problems solved by technology

In terms of composition design, the addition range of C, Mn, Nb, and V is narrow, and Mo is an essential element, which increases the production cost

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