EH47 crack arrest steel for large container ship and manufacture method thereof

Abstract

The invention relates to EH47 crack arrest steel for a large container ship. The chemical components of a steel plate comprise, by mass, 0.03%-0.06% of C, 0.15%-0.50% of Si, 1.50%-2.00% of Mn, smallerthan or equal to 0.008% of P, smaller than or equal to 0.0050% of S, 0.050%-0.080% of Nb, 0.020%-0.050% of V, 0.008%-0.020% of Ti, 0.80%-1.30% of Ni, 0.10%-0.30% of Cr and 0.10%-0.30% of Cu. The manufacture technology process of the steel plate comprises the steps of smelting, continuous casting, reheating, TMCP rolling and controlled cooling. The steel plate obtains fine and uniform acicular ferrite in the whole thickness, the strength is moderate, the toughness is excellent, the good brittle fracture resistance is achieved, namely, the CTOD characteristic value delta is larger than or equal to 0.15 mm at -60 DEG C, and the crack arrest performance is excellent, namely, Kca is larger than or equal to 6,500 N/mm<3/2>.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to EH47 crack arrest steel for large container ships and a preparation method thereof. Background technique [0002] The development of the world economy and the growth of trade have promoted the rapid development of the shipping industry and accelerated the development of the shipbuilding industry. Container ships are developing rapidly in the direction of large-scale. The 10,000TEU ultra-large container ship has been widely used, and the 18,000-23,000TEU ultra-large container ship has entered the stage of actual ship construction. The increasing size and super-large size of container shipping requires the use of high-strength thick plates during the construction process to ensure the strength and stiffness of the hull structure, but at the same time, the low crack resistance of high-strength thick plates will lead to low-stress brittle fracture of the structure...

AI Technical Summary

Problems solved by technology

However, this method uses low-temperature impact toughness and NDT ductile-brittle transition temperature to measure the crack arrest performance of the steel plate, which is not scientific and rigorous. It can only show that the toughness of the steel plate is better than that of brittle fracture resistance, and it cannot prove the crack arrest performance of the steel plate. Excellent performance, and only the ESSO test or double tensile test is an internationally recognized standard test for measuring the crack arrest performance of steel plates

[0008] Therefore, the existing technology cannot fully meet the requirements of high strength, high impact toughness and crack arrest performance of EH47 steel.

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