High-toughness steel plate used in extremely cold environment and manufacturing method thereof

Abstract

The invention discloses a high-toughness steel plate used in an extremely cold environment. The high-toughness steel plate comprises the following chemical elements in percentage by mass: 0.05-0.16% of C; 0.60%-1.2% of Si; 0.40% to 1.20% of Mn; 0.30% to 1.00% of Cr; 0.40% to 1.00% of Ni; 0.01% to 0.10% of Ti; 0% to 0.60% of Mo; 0.30% to 0.80% of Cu; 0.01% to 0.06% of Al; 0.003%-0.06% of Nb, 0%-0.08% of V and the balance Fe and other inevitable impurities. In addition, the invention also discloses a manufacturing method of the high-toughness steel plate, which comprises the following steps: (1)smelting and casting; (2) heating; (3) rolling; and (4) quenching and tempering. The high-toughness steel plate has the characteristics of high strength, high toughness, excellent weldability, good surface quality and stable whole plate performance.

Description

technical field [0001] The invention relates to a steel plate and a manufacturing method thereof, in particular to a high-toughness steel plate and a manufacturing method thereof. Background technique [0002] Ships built for polar regions need to be used in low-temperature and cold seas, and the marine environment is complex and changeable, so they have to withstand many challenges brought about by ultra-low temperature, ice and snow abrasion, low-temperature wind wave collision, strong ocean storm and frozen soil collision. The design, material selection, construction and processing of low-temperature steel for ships have put forward higher requirements. Therefore, the low-temperature steel used in polar ships requires excellent comprehensive performance in extreme cold and low temperature, and its structural materials not only need to have high strength and good plasticity, but also need to have excellent impact toughness at -60°C and -80°C , especially in the ultra-low ...

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Problems solved by technology

[0008] However, it should be pointed out that the chemical composition ratio of the steel plate obtained in this patent document is uncertain, which may easily lead to poor performance stability in mass production of the steel plate, or add excessive alloy elements to ensure performance stability, but it will inevitably cause production costs. too high

In addition, the starting temperature of the c finish rolling is controlled below the Ar3 temperature and the steel plate is rolled back to the temperature. It can be carried out for large thickness specifications, but it will be accompanied by the problems of slow production rhythm and low efficiency. For thin gauge steel plates, due to the steel plate itself The temperature drop is fast, so the core temperature recovery process using the steel plate has poor adaptability, it is difficult to guarantee the performance of the steel plate, the actual implementation is difficult, and the effect is poor

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