X65 hot-rolled coil for use in acidic environment and manufacturing method thereof

Abstract

The invention relates to an X65 hot-rolled coil for use in an acidic environment and a manufacturing method thereof. The X65 hot-rolled coil comprises the following components by weight percent: 0.02-0.06 weight percent of carbon, 0.15-0.25 weight percent of silicon, 0.80-1.20 weight percent of manganese, 0.02-0.05 weight percent of niobium, 0.020-0.040 weight percent of vanadium, 0.010-0.020 weight percent of titanium, less than or equal to 0.30 weight percent of copper, less than or equal to 0.30 weight percent of nickel, 0.10-0.30 weight percent of Cr, less than or equal to 0.015 weight percent of phosphorus, less than or equal to 0.0015 weight percent of sulfur, 0.0020-0.0050 weight percent of calcium, more than or equal to 2.0 weight percent of Ca / S, less than or equal to 0.0005 weight percent of boron and less than or equal to 0.006 weight percent of nitrogen. Other components are ferrum and trace impurities. The steelmaking process route and key control points are hot metal pretreatment, converter steelmaking, LF furnace refining, RH furnace refining, slab casting, billet finishing and storage. The refining procedures outside the furnaces comprise Ca treatment to modify inclusions. The key points of the rolling process are as follows: the heating temperature is 1150-1200 DEG C, the rough rolling outlet temperature is 920-1020 DEG C, the final rolling temperature is 780-860 DEG C, and the rolling temperature is 560-620 DEG C. The invention adopts low-price alloy (Cr and V) to substitute expensive alloy (Mo and Nb) so as to produce steel hot-rolled coils for X65 pipelines with more stable performance and lower alloy cost. Moreover, the hot-rolled coils for X65 pipelines have anti-HIC performance, high strength and high toughness.

Description

[0001] Field [0002] The invention relates to an X65 hot-rolled coil for acidic environment and a manufacturing method thereof, which belongs to the field of new iron and steel materials and steel rolling, and is particularly suitable for pipeline steel for high-pressure and long-distance transportation pipelines in acidic environment. Background technique [0003] At present, the steel pipes used for transporting oil and natural gas refer to the API 5L standard of the American Petroleum Institute, including hot-rolled coils for spiral submerged arc welded pipes and steel plates for longitudinal submerged arc welded pipes. Flat plate production of longitudinal submerged arc welded pipe. With the increase of delivery pressure, the delivery contains H 2 The oil and natural gas medium of S put forward higher performance requirements for long-distance transmission steel pipes and pipeline steels. On the one hand, pipeline steels are required to have higher strength and excellent...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a kind of X65 hot-rolled coil for sour environment and its manufacturing method. Stable, HIC-resistant, high-strength and high-toughness X65 pipeline steel hot-rolled coils with lower alloy cost

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