Steel for upper deck of cargo oil tank of tanker

Abstract

The invention provides steel for the upper deck of a cargo oil tank of a tanker, which belongs to the technical field of ship plate steel. The steel comprises the following chemical components expressed in mass percentage: C 0.01 to 0.3%, Si 0.02 to 2.0%, Mn 0.05 to 2.0%, S <= 0.01%, P<= 0.05%, Ni 0.05 to 2.0%, Cu 0.05 to 2.0%, Cr 0.005 to 1.0%, Zr 0.005 to 0.2% and Hf 0.005 to 0.2%, with the balance being Fe. As needed, the steel also comprises one or more selected from the group consisting of 0.0005 to 0.2% of Ca, 0.0005 to 0.2% of Mg, 0.0005 to 0.2% of Sr and 0.0005 to 0.2% of Ba, and / or one or more selected from the group consisting of 0.0005 to 0.3% of Sn, 0.0005 to 0.3% of Sb and 0.0005 to 0.3% of Te, and / or one or more selected from the group consisting of 0. 0005 to 0.3% of W, 0.0005 to 0.3% of Mo, 0.0005 to 0.3% of Co and 0.0005 to 0.3% of REM. The steel has the advantages of excellent general corrosion resistance, greatly reduced maintenance cost and effectively improved reliability of the upper deck of the cargo oil tank in a service process.

Description

technical field [0001] The invention belongs to the technical field of ship plate steel, in particular to a steel used for the upper deck of an oil tanker's cargo oil tank. It shows excellent corrosion resistance in the cargo oil tank environment of tankers, can inhibit the occurrence of uniform corrosion, and can significantly reduce the formation of solid S in corrosion products. Background technique [0002] In actual cargo oil tanks of large oil tankers, inert gas (in O 2 : 5% by volume, CO 2 %: 13% by volume, SO 2 : 0.01% volume, the balance is N 2 ), the O in this inert gas 2 , CO 2 , SO 2 and H volatilized from crude oil 2 Corrosive gases such as S will be enriched on the upper inner surface of the tanker's cargo oil tank (the inner surface of the upper deck), resulting in severe uniform corrosion, and the corrosion rate is above 0.3mm / year. At the same time, because the deck temperature alternates between day and night, the inner surface of the upper deck is ...

AI Technical Summary

Problems solved by technology

However, due to the large internal area of ​​the cargo oil tank, and the need to re-coat once every 10 to 15 years, a large amount of construction and inspection costs are required. Physical health also poses a threat

[0004] Aiming at the corrosion problem of oil tankers, Patent Document 1 provides a kind of corrosion-resistant steel for ships, which adds an appropriate amount of W, Cr and other elements to the steel to improve the corrosion resistance of the steel. environment, and the corrosion environment of cargo oil tanks is very different from that of ballast tanks. For this reason, Patent Document 2 discloses a corrosion-resistant steel for cargo oil tanks, which is characterized in that the mass percentage of C is 0.01- Add appropriate amount of Si, Mn, P, S and Ni, Cu, Cr, Ti to 0.2% steel, and selectively add W, Mo, Co, Sb, Sn, Nb, V, B. In this method, Although it can improve the corrosion resistance of steel, there will be H during the transportation of crude oil 2 The volatilization of S gas, and this patent document does not consider the content of H 2 Corrosion in case of S

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