Slurry feed line steel with good low-temperature toughness and manufacturing method thereof

Abstract

The invention provides slurry feed line steel with good low-temperature toughness and a manufacturing method thereof. The slurry feed line steel with good low-temperature toughness comprises 0.10 to 0.20% of C, 0.10 to 0.30% of Si, 0.80 to 1.50% of Mn, less than or equal to 0.018% of P, less than or equal to 0.004% of S, 0.010 to 0.035% of Ti, 0.02 to 0.05% of Als, less than or equal to 0.006% of N and the balance Fe. The manufacturing method of the slurry feed line steel with good low-temperature toughness comprises smelting, continuous casting and hot rolling. When a plate blank is heated to a temperature of 1160 to 1300 DEG C, the plate blank is subjected to a first-stage controlled rolling and a second-stage controlled rolling, wherein an initial temperature of the first-stage controlled rolling is in a range of 1130 to 1200 DEG C; an end temperature of the first-stage controlled rolling is above 1020 DEG C; an initial temperature of the second-stage controlled rolling is below 1000 DEG C; and an end temperature of the second-stage controlled rolling is in a range of 780 to 880 DEG C. The plate blank subjected to the first-stage controlled rolling and the second-stage controlled rolling is cooled at a speed of 5 to 20 DEG C per second and then is reeled at a temperature of 550 to 680 DEG C. The manufacturing method of the slurry feed line steel with good low-temperature toughness has the advantages that the slurry feed line steel with good low-temperature toughness does not contain precious alloy elements such as Nb, Mo, V and the like so that an alloy cost is low; S content and P content are controlled strictly so that good low-temperature toughness of steel is guaranteed effectively; and a controlled rolling and controlled cooling technology is utilized for crystal particle refinement so that a pearlite microstructure is uniformly distributed and good steel strength matching with toughness is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a steel for slurry conveying pipeline whose hot-rolled performance can reach B-X60 steel grade in APISpec 5L standard and a manufacturing method thereof. Background technique [0002] Pipeline transportation is the most economical, safe, efficient and environmentally friendly transportation method for long-distance transportation of oil, natural gas, coal slurry, etc. As the technology of pipeline transportation of coal slurry and various ore slurries has fully matured, it is expected that by 2010, China will Coal slurry pipelines with a total length of about 5000-6000km have been built, and many slurry pipelines are being or will be built. [0003] The steel used for pipelines for slurry transportation meets the American National Standard ASME B31.11-2002 and the American Petroleum Institute API SPEC 5L specification. Arc welded steel pipe (SSAW or...

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Problems solved by technology

[0041] The object of the present invention is to overcome the deficiency that above-mentioned prior art exists, as in composition design, or adopt low C to add elements such as noble metal Mo, V, Nb, alloy cost is high; Or adopt high C and high Si etc. alloy design, weldability and poor low-temperature toughness, etc., to provide a pipeline steel for slurry transportation that can not only meet the reasonable matching of strength and toughness of ordinary pipeline steel and weldability, but also has certain wear resistance and good low-temperature performance and its manufacturing method

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