Method for producing X65 acid-resistant pipeline steel plate used under low-cost and ultralow-temperature conditions through curling furnace

Abstract

The invention relates to a method for producing an X65 acid-resistant pipeline steel plate used under the low-cost and ultralow-temperature conditions through a curling furnace. According to the method, the process comprises the steps of KR molten iron pretreatment (advanced desulfurization), BOF smelting, RH vacuum degassing, LF refining, RH vacuum degassing, continuous casting to form a continuous casting billet with the thickness of 150 mm, continuous casting billet covering slow cooling, continuous casting billet checking and cleaning, casting billet reheating, high-pressure water descaling, rolling, flying shear segmentation, ACC cooling, straightening, steel plate shearing and inspection and warehousing. The method has the advantages that the yield strength of the steel plate is 460-600 MPa, the tensile strength is 550-700 MPa, the elongation rate is greater than or equal to 30%, the yield strength ratio Rt0.5 / Rm is less than or equal to 0.90, and the product can meet the use requirements under the ultralow-temperature and acid service conditions that the Charpy impact energy at -60 DEG C is greater than or equal to 100J and the drop hammer shear area at -50 DEG C is greaterthan or equal to 85%.

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 energy supply relationship will lead to the construction of new oil and gas pipeline projects, which will drive the increase in the market demand for pipeline steel. However, with the continuous development of oil and natural gas, high-quality, easy-to-exploit oil and natural gas are constantly decreasing. Many oil and natural gas that are located in severe cold areas or need to pass through severe cold areas, and contain corrosive gases, and the exploitation of natural gas show an increase year by year. trend. Today, most of the newly discovered oil fields are located in remote areas with harsh climate conditions, such as Siberia gas fields and North Alaska gas fields. With the development of oil and gas fi...

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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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