A hot-rolled coil of high-silicon and low-manganese pipeline steel and its production method

Abstract

The invention provides a high-silicon low-manganese pipeline steel hot-rolled coiled plate and a production method thereof. The coiled plate comprises the following components of, by weight, 0.07-0.12% of C, 0.40-0.75 % of Si, 0.60-0.95 % of Mn, less than or equal to 0.020 % of P, less than or equal to 0. 006 % of S, 0.015-0.06 % of Nb, and 0.04-0.10 % of V, less than or equal to 0.030 % of Ti, less than or equal to 0. 30 % of Cr, 0.020-0.050 % of Alt, the balance Fe and inevitable impurities. The production method includes molten iron pretreatment, converter smelting, LF furnace external refining, continuously casting, casting blank heating, controlling rolling, controlling cooling and reeling. According to the high-silicon low-manganese component hot-rolled coiled plate, the component design breaks through the range of API requirements, but the corresponding production and rolling process design is adopted, the requirements of the API 5L standard mechanical property are met, the transverse longitudinal stretching performance difference is small, and good impact toughness is achieved.

Description

technical field [0001] The invention belongs to the field of high-strength low-alloy steel, and in particular relates to a hot-rolled coil for pipeline steel with high silicon and low manganese and good horizontal and vertical properties and a production method thereof. Background technique [0002] At this stage, the steel coils for oil and gas transmission spiral / straight seam pipelines have been successfully developed in China and mass-produced with stable performance. However, in the past, domestically produced pipeline coils were designed with low-silicon and high-manganese components, and pipeline steel hot-rolled coils with high-silicon and low-manganese components were designed, and no related reports have been seen. [0003] From the perspective of alloy design, the main role of manganese in pipeline steel is to be a good deoxidizer and desulfurizer, which can improve its strength and hardness; while the role of silicon in steel is to improve strength, but at the sa...

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Problems solved by technology

[0006] The chemical composition of the steel plate disclosed in "A Steel Plate for Making Submarine Pipeline and Its Rolling Method" (publication number: CN 101082108 A) not only includes C0.030-0.075, Si0.10-0.30, Mn1.40- 1.60, Nb0.03-0.05, V≤0.060, Ti0.001-0.02, Cr≤0.20, and Ni0.10-0.25, Mo0.07-0.20, Cu≤0.20, the disadvantage is that the alloy design cost is high ; Secondly, this invention product adopts 200-300mm middle slab to produce

[0009] "X56 pipeline steel and production method therefore" (publication number: CN101899617A) used in this invention are 0.060-0.090wt% of carbon, 0.20-0.30wt% of silicon, 1.30-1.50wt% of manganese, less than or equal to 0.008wt % of sulfur, less than or equal to 0.020wt% of phosphor, 0.035-0.055wt% of niob, which is designed with low silicon and high manganese components required by API, and the addition of Ni increases the production cost

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