High-toughness quantitative-reduction ship plate marine steel and preparation method thereof

Abstract

The invention discloses high-toughness quantitative-reduction ship plate marine steel. A steel plate comprises the following chemical components by weight percent: 0.04%-0.14% of C, 0.15%-0.45% of Si,0.90%-1.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.010% of S, 0.010%-0.040% of Nb, 0-0.20% of Cr, 0-0.030% of V, 0.005%-0.020% of Ti, 0.015%-0.050% of Als, less than or equal to 30 ppm of N, less than or equal to 30 ppm of O, less than or equal to 2 ppm of H, and the balance Fe and inevitable impurities, wherein Als is acid-soluble aluminum; a welding crack sensitivityindex (Pcm) of the steel plate is less than or equal to 0.22%; and a carbon equivalent value (CEV) is less than or equal to 0.39%. The steel plate is not liable to be broken and damaged, and has goodstrength and toughness, welding performance and crack arrest performance.

Description

technical field [0001] The invention belongs to the technical field of iron and steel, and in particular relates to a high-toughness reduction ship plate marine steel and a preparation method thereof. Background technique [0002] By controlling the cooling rate of the steel plate after rolling, a large number of dislocations and deformation bands generated during the rolling process can be retained in the steel plate structure to the greatest extent, which can play a significant strengthening role, reduce the amount of precious alloys added, reduce the hardenability of the steel plate, and improve Steel plate welding performance. However, in the process of water cooling, the uniformity of the thickness direction of the steel plate has always been a problem. How to effectively master the cooling process to promote the uniformity of the thickness direction of the steel plate, the strength, impact, and transverse and longitudinal properties of the steel plate near the surface,...

AI Technical Summary

Problems solved by technology

Although the cost of this component system is low, the production specifications are limited, and it is difficult to meet the market demand for extra-thick specifications.

[0008] After analyzing the existing technology, it is found that the TMCP ship plate marine steel in the published literature has high alloy cost, difficult production, and poor technical promotion; or the low-cost system is adopted, but the thickness specification that can be produced is limited or The toughness level is low, it is difficult to meet the market demand

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