High-strength ship hull structural steel and production method of plate roll

Abstract

The present invention relates to low alloy steel and is especially steel for hull structure and its production process. The steel for hull structure consists of C 0.03-0.075 wt%, Si 0.01-0.35 wt%, Mn 1.40-1.60 wt%, Als 0.015-0.100 wt%, V 0.020-0.080 wt% and Fe and impurity elements for the rest. It is produced in a CSP production line with special temperature system, reduction schedule and cooling system, and through casting blank, hydraulically shearing, heating and descaling, rolling into strip steel, stream cooling and finally winding. It has the advantages of less alloy elements, simple production process, high production efficiency, low power consumption, high product performance, etc.

Description

technical field [0001] The invention belongs to low-alloy steel, in particular to steel for ship hull structure and its production method. Background technique [0002] With the development of the shipbuilding industry, ordinary marine steel plates can no longer meet the requirements of large-scale and professional ships, and people prefer low-alloy steel with excellent performance. Chinese national standard GB712-2000 discloses high-strength ship steel composition (wt%) C≤0.18%, Si≤0.50%, 0.90-1.60% Mn, Als≥0.015, 0.02-0.05% Nb, 0.05-0.10% V, Ti≤0.02%, Cu≤0.35%, Cr≤0.02%, Ni≤0.40%, Mo≤0.08%, and the rest are Fe and impurity elements. There are as many as 11 alloying elements in this kind of steel. The disadvantage is that there are many kinds of alloys to be added, and some alloying elements are expensive, which increases the cost of steelmaking and brings inconvenience to steelmaking production. Nowadays, steel plates for hull structures are mostly produced by convention...

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Problems solved by technology

Its disadvantages are complex process, many equipments, long production line and high infrastructure investment; long production cycle, which takes more than 2 days from smelting molten steel to rolling into ship plate, which takes up a lot of working capital; secondary heating of slab, high energy consumption; The heating temperature of the slab is unstable, and the cross-section temperature distribution along the length and width direction is uneven, which affects the performance of the ship plate, and affects the accuracy of the thickness, convexity, flatness and width of the plate; the finished product rate is low, generally 88%; due to the Due to the limitations of rolling mills and other aspects, it is even more difficult to produce thin-gauge ship plates

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