Hot-rolled steel plate for ultra-wide thick-wall X80-grade pipeline and production method of hot-rolled steel plate

Abstract

The invention discloses a hot-rolled steel plate for an ultra-wide thick-wall X80-grade pipeline and a production method of the hot-rolled steel plate. The steel plate comprises the following components: 0.03%-0.05% of C, 0.16%-0.28% of Si, 1.50%-1.75% of Mn, 0.05%-0.08% of Nb, 0.012%-0.025% of Ti, 0.10%-0.25% of Cr, 0.01%-0.04% of V, smaller than or equal to 0.19% of Mo, smaller than or equal to0.20% of Ni, smaller than or equal to 0.14% of Cu, smaller than or equal to 0.020% of Al, smaller than or equal to 0.013% of P, smaller than or equal to 0.0015% of S, 0.0005%-0.0020% of O, 0.001%-0.004% of N, 0.0010%-0.0045% of Ca, 0.40%-0.65% of Mo+Ni+Cr+Cu, and the balance of iron and inevitable impurities, wherein Ca/S is larger than or equal to 1.6. The rough rolling starting temperatureis 1070-1150 DEG C, and the finish rolling starting temperature is 820-860 DEG C. The final rolling temperature is 760-780 DEG C, and the cooling temperature is 730-770 DEG C. The width of the steelplate is larger than 4000 mm, and the thickness of the steel plate is larger than 25 mm. The steel plate is good in low-temperature toughness and low in yield ratio.

Description

technical field [0001] The invention belongs to the technical field of low-carbon low-alloy steel, and in particular relates to an X80-grade high-strength, high-toughness, low-yield-ratio hot-rolled steel plate for oil and gas transmission pipelines with a thickness > 25 mm and a width > 4000 mm and a production method thereof. Background technique [0002] In order to improve the efficiency of oil and gas transmission, the transmission pressure and diameter of long-distance oil and gas pipelines continue to increase. The maximum diameter of steel pipes required for oil and gas pipeline construction has reached φ1422mm. At the same time, in order to ensure safety, the strength level and thickness of steel pipes are also increasing. The corresponding pipeline steel plate must meet the requirements of thick wall (>25mm), large plate width (>4000mm), and high steel grade (X80 grade). [0003] On the other hand, the world's oil and natural gas consumption continues t...

AI Technical Summary

Problems solved by technology

[0012] The purpose of the present invention is to overcome the deficiencies in the prior art, solve the control problems of ultra-wide and thick-walled X80 grade pipeline steel such as strength-plastic-toughness matching, microstructure selection and uniformity, and low-temperature toughness, and provide a kind of oil and gas transportation with a thickness > 25mm and a width > 4000mm X80 grade high-strength, high-toughness, low yield ratio hot-rolled steel plate and production method thereof

Images