Novel high-strength weather-resistant pipeline steel X80 steel plate and production method thereof

Abstract

The invention discloses a novel high-strength weather-resistant pipeline steel X80 steel plate with a thickness of less than 40 mm and a production method thereof. The novel high-strength weather-resistant pipeline steel X80 steel plate comprises the following chemical components of C, Si, Mn, N, V, Ti, Ni, Cr, Ce, La, Cu, Mo, Als, P, S, and the balance Fe and residual elements. The steel plate has an acicular ferrite structure; through process control of converter smelting, VD + LF + VD smelting, continuous casting, heating, controlled rolling and controlled cooling and the like, the yield strength of the obtained steel plate ranges from 562 MPa to 680 MPa, the tensile strength ranges from 675 MPa to 790 MPa, the elongation can be controlled to range from 25% to 30%, and the V-shaped-30 DEG C longitudinal impact energy is controlled to range from 180 J to 315 J; the average value of-15 DEG C drop-weight tear experiments is 90%, the welding crack sensitivity coefficient Pcm is less than or equal to 0.25, the weather resistance index is larger than or equal to 6.0, meanwhile, HIC and SSCC experiments both pass the test, and the standard requirement of X80 pipeline steel is completely met.

Description

technical field [0001] The invention relates to steel products, in particular to a novel high-strength weather-resistant pipeline steel X80 steel plate and a production method thereof. Background technique [0002] X80 belongs to the American standard API5L medium and high strength pipeline steel, which has the characteristics of high strength, excellent low temperature toughness, good processing performance and welding performance. With the substantial increase in the demand for oil and natural gas, the transportation capacity has been greatly developed, and higher requirements are put forward for the quality of pipeline steel, such as weather resistance and service life. At present, the pipeline steel produced in China mainly depends on the surface coating 1. Apply anti-corrosion layer to improve weather resistance. On the one hand, paint and anti-corrosion layer pollute the environment and do not meet the current environmental protection development requirements. On the o...

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Problems solved by technology

With the substantial increase in the demand for oil and natural gas, the transportation capacity has been greatly developed, and higher requirements are put forward for the quality of pipeline steel, such as weather resistance and service life. At present, the pipeline steel produced in China mainly depends on the surface coating 1. Apply anti-corrosion layer to improve weather resistance. On the one hand, paint and anti-corrosion layer pollute the environment and do not meet the current environmental protection development requirements. On the other hand, it also increases production costs and maintenance costs. Improve the quality of pipeline steel while improving environmental protection. Sex, and can reduce production and later costs, become the current or next development direction

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