A method for producing x65 acid-resistant pipeline steel plates used under low-cost and ultra-low temperature conditions by a coiling furnace

Abstract

The invention relates to a method for producing low-cost X65 acid-resistant pipeline steel plates used under ultra-low temperature conditions by a coiling furnace. The process is: KR molten iron pretreatment (desulfurization in advance)—BOF smelting—RH vacuum degassing—LF refining—RH vacuum degassing Gas—Continuous casting into 150mm thick continuous casting slab—Continuous casting slab with cover and slow cooling—Continuous casting slab inspection and cleaning—Casting slab reheating—High pressure water descaling—Rolling-Flying shear segmentation—ACC cooling—Straightening— Steel plate shearing—inspection and storage. The yield strength of the steel plate is 460-600MPa, the tensile strength is 550-700MPa, the elongation is ≥30%, and the yield ratio Rt 0.5 / Rm≤0.90, the product can meet the requirements of ultra-low temperature and acid service conditions with Charpy impact energy ≥ 100J at ‑60°C and drop weight shear area ≥85% at ‑50°C.

Description

technical field [0001] The invention relates to X65MS acid-resistant pipeline steel and a manufacturing method thereof, in particular to a manufacturing method of thinner and longer specification products of the steel plate. Background technique [0002] Changes in the supply relationship of energy will lead to the construction of new oil and gas pipeline projects, driving the increase in the market demand for pipeline steel. However, with the continuous development of oil and natural gas, the number of high-quality and easy-to-exploit oil and natural gas is decreasing. Many oil and natural gas are located in severe cold areas or need to pass through severe cold areas, and the exploitation of oil and natural gas with corrosive gas is increasing year by year. trend. Today, most of the newly discovered oil fields are located in remote areas with harsh climatic conditions, such as the Siberian gas field and the North Alaska gas field. With the development of oil and gas field...

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Problems solved by technology

[0004] Now some X65MS acid-resistant pipeline steel plates are also designed with low-carbon + micro-alloy composite added components, but it is difficult to ensure the low-cost, ultra-low temperature and acid-resistant performance of rolling at the same time. A kind of acid corrosion resistant X65MS pipeline steel and its preparation method, non-rolling low-cost process, and the patent C content is between 0.04-0.06%, it is difficult to guarantee the ultra-low temperature performance and HIC resistance performance of thin acid-resistant steel plates; such as the patent The patent document with the notification number CN109047694A discloses an economical HIC-resistant pipeline steel plate X65MS delivered by TMCP and its manufacturing method, which is not a rolling process. The C content of this patent is between 0.06-0.10%, which is difficult to guarantee the use in an ultra-low temperature environment ; Such as the patent document of patent No. CN102699022A discloses a kind of control method of hot-rolled limit specification steel coil of single stand steckel mill, produces the pipeline steel plate of ultra-thin specification, but belongs to non-acid-resistant steel plate from the disclosed chemical composition

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