Wear-resistant corrosion-resistant steel plate with hardness of 500 HB and for slurry dredging, and production method thereof

Abstract

The invention provides a wear-resistant corrosion-resistant steel plate with hardness of 500 HB and for slurry dredging, and a production method thereof. The steel plate comprises, by weight, 0.25 to0.28% of C, no more than 0.01% of Si, 1.3 to 1.6% of Mn, no more than 0.015% of P, no more than 0.005% of S, 0.2 to 1.0% of Al, 0.3 to 1.2% of Cr, 0.001 to 0.002% of B, no more than 0.005% of N, and one or more selected from a group consisting of 0.01 to 0.03% of Nb and 0.01 to 0.025% of Ti, with the balance being Fe and unavoidable impurity elements, wherein the sum of Nb and Ti is more than 6.65N and no more than 0.045. The wear-resistant corrosion-resistant steel plate has yield strength of 1200 MPa or more, tensile strength of more than 1500 MPa, elongation of no less than 8%, hardness of500+ / -30 HBW, and the impact energy value at -40 DEG C of more than 20 J. The composition design of the wear-resistant corrosion-resistant steel plate allows the steel plate to have both corrosion resistance and wear resistance; and the steel plate is mainly applied to manufacturing of dredging pipelines applied to reclamation of land from water, navigation channel dredging and other fields and has wear and corrosion resistance 2.5 times higher than the wear and corrosion resistance of conventional common pipes, so dredging efficiency is greatly improved and operation cost is lowered.

Description

Technical field [0001] The invention relates to the field of low-alloy steel manufacturing, in particular to a wear-resistant steel plate for a slurry dredging pipe with a hardness of 500HB and a production method thereof. Background technique [0002] In operations such as sea reclamation, channel dredging, and bank maintenance, a large amount of solid particles such as sand and gravel are transported in the form of slurry through the dredging pipeline for long distances. The pipe body is subjected to the electrochemical corrosion of the slurry medium and the solid particles. Abrasion and the interaction between the two, especially when the seawater slurry contains weathered rock, coral reef, and medium-coarse sand, will cause more serious abrasion on the pipe body. Common Q235B and Q345B pipelines have a longer service life under harsh working conditions. Short, even scrapped after less than one year. [0003] Wear-resistant steels such as "HB500 wear-resistant steel plate and i...

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Problems solved by technology

Although the steel involved has high hardness and wear resistance, a large number of carbide particles in the matrix play the role of "cathode" under the conditions of corrosion and wear, which promotes the occurrence of electrochemical corrosion, reduces corrosion resistance, and deteriorates the material. It is difficult to meet the abrasive requirements of large particle size and high content slurry in slurry dredging environment

[0005] Chinese Patent Publication No. CN101886225A (Comparative Patent 2) discloses "a corrosion-resistant and wear-resistant steel and its preparation method". This patent involves the addition of 0.4-0.9% C, 14-16% Mn, and Mo, Cr The content is all at 5-10%, and also contains a certain amount of rare elements such as Pr, Nd and Gd in addition, belongs to the high-alloy steel type, and the cost is very high; Lower bainite wear-resistant steel pipe for body transportation and its manufacturing method" and "a wear-resistant steel for slurry conveying welded pipe line and its manufacturing method" disclosed in Chinese Patent Publication No. CN103436790A (comparative patent 3), these two patents involve The steel types are all bainite or bainite + acicular ferrite structure, the hardness of the matrix is ​​not high, and the tensile strength is only 600-800MPa. It is mainly used for fine-grained (tens of μm) ore slurry or crude oil transportation with slight wear It is not suitable for the large particle and high density seawater slurry transportation field

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