Polar region ship steel plate capable of high heat input welding and making method for same

Abstract

The invention relates to a polar region ship steel plate capable of high heat input welding. The steel plate comprises the following chemical components in percentage by mass: 0.03-0.07% of C, 0.15-0.30% of Si, 1.10-1.50% of Mn, less than or equal to 0.070% of P, less than or equal to 0.0030% of S, 0.008-0.020% of Ti, 0.0030-0.0060% of N, 0.10-0.30% of Cu, 0.10-0.40% of Ni, 0.010-0.040% of Nb, 0.020-0.050% of Al and the balance of Fe; the matrix structure of the steel plate is ferrite and pearlite; the pearlite is dispersedly distributed among the ferrite crystalline grains; and the size of the ferrite crystalline grains is 4-8 mu m. The steel plate has excellent 60-80 DEG C low-temperature impact toughness and low-temperature strain ageing resistance; and the welding performance is excellent through high-efficient welding of highest heat input of 200 KJ / cm.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a steel plate for polar ships, which has excellent low-temperature impact toughness and strain aging performance, and can be welded with large input energy. Background technique [0002] Ships built for polar regions, because they are used in cold sea areas, require their structural materials not only to have high strength, good plasticity but also to have high impact toughness at extremely low temperatures (-60°C, -80°C) . Generally, polar marine steel is required to have high strength with yield strength ≥ 355MPa, tensile strength ≥ 490MPa, and excellent low-temperature impact toughness at -60°C and -80°C. In addition, due to the complex and changeable marine environment, polar ships often have to withstand the strong effects of typhoons (hurricanes), waves, tides, ocean currents, ice, etc. [0003] In addition, the shipbuilding and offshore engineering ma...

AI Technical Summary

Problems solved by technology

[0006] To sum up, the existing technology cannot fully meet the needs of polar ships. It must have good impact toughness at extremely low temperatures (-60°C, -80°C), extremely low-temperature strain aging properties, and large wires. Comprehensive requirements for energy welding

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