Low-cost acid resistant pipeline steel hot-rolled plate and manufacturing method thereof

Abstract

The invention discloses a low-cost acid resistant pipeline steel hot-rolled plate and a manufacturing method thereof. The hot-rolled plate consists of the following components in percentage by weight: 0.04 to 0.10 percent of C, 0.05 to 0.50 percent of Si, 1.00 to 1.70 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.002 percent of S, less than or equal to 0.08 percent of Nb, 0.005 to 0.030 percent of Ti, 0.010 to 0.050 percent of Als, 0.0010 to 0.0040 percent of Ca, less than or equal to 0.0060 percent of N, less than or equal to 0.0002 percent of H, less than or equal to 0.0010 percent of O, and the balance of Fe and inevitable impurities. The nonmetallic inclusions A / B / C / D are less than or equal to grade 2.0, and the pearlite belt tissues are less than or equal to grade 2.0. The manufacturing method for the hot-rolled plate is characterized by comprising the following steps of: directly feeding the components into a heating furnace at the temperature of between 500 and 850 DEG C after continuous casting is finished to perform heating, and discharging the heated product at the temperature of between 1,150 and 1,250 DEG C to perform rolling; controlling rolling of a rough mill and a finishing mill at two stages, wherein the final rolling temperature of rough rolling is between 950 and 1,050 DEG C, the final rolling temperature of finish rolling is between 770 and 870 DEG C, and the finish rolling compression ratio is more than 60 percent; and controlling cooling by adopting a laminar flow cooling device after rolling, wherein the cooling speed is 8 to 20 DEG C per second, and the final cooling temperature is between 550 and 700 DEG C.

Description

Technical field [0001] The invention relates to a high-strength low-alloy steel, in particular to a low-cost acid-resistant pipeline steel and a method for manufacturing a hot-rolled coil. Background technique [0002] Pipeline transportation is the most economical, safe, efficient and environmentally friendly transportation method for long-distance transportation of oil and natural gas. In oil and natural gas transportation, raw gas transportation from gas wells to gas gathering stations is H 2 The S content is high, the gas pipeline has been in an acidic environment for a long time, ordinary pipeline steel pipes do not have the ability to resist HIC and SSCC, and contain H at home and abroad. 2 Gas pipelines with higher S, especially gas gathering pipelines in oil and gas fields, basically use special acid-resistant pipeline steel pipes to ensure the safe operation of gas pipelines. [0003] Acid-resistant pipeline steel pipe generally follows the requirements of Appendix H of the...

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Problems solved by technology

[0005] The acid-resistant pipeline steel part disclosed in the above patent documents is seamless steel pipe or hot-rolled steel plate, and the rest is coiled plate but cannot have HIC and SSCC resistance properties at the same time. At the same time, precious alloy elements such as Ni, Cu, and Mo need to be added, costing High; the continuous casting slab needs to be cleaned off the production line before heating and rolling production, resulting in large heat loss, long production cycle and high production cost

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