440 MPa corrosion resisting steel for ship at low temperature environment and production method of corrosion resisting steel

Abstract

The invention discloses a corrosion-resistant steel for 440MPa ships in a low-temperature environment and a production method thereof, belonging to the technical field of material steel. It includes the following components in mass percentage: C: 0.031-0.105%, Si: 0.18-0.65%, Mn: 0.52-2.05%, P≤0.009%, S≤0.001%, Als: 0.080-0.200%, Nb: 0.021 to 0.070%, Ti: 0.045 to 0.125%, Ni: 0.10 to 0.35%, and the balance is Fe and unavoidable impurities. The production method is 1) conventional molten iron desulfurization; 2) converter smelting and RH vacuum treatment; 3) billet continuous casting and heating; 4) section rolling; 5) cooling. The prepared steel plate can be used in an extremely cold and low temperature environment of around ‑80°C. The yield strength of the steel plate is ≥440Mpa, the impact toughness KV2≥100J, and the seawater corrosion performance is better than the traditional seawater corrosion-resistant steel 10CrMoAl.

Description

technical field [0001] The invention relates to a steel for marine engineering and a production method thereof, belonging to the technical field of material steel, in particular to a corrosion-resistant steel for ships of 440MPa grade in a low-temperature environment and a production method thereof. Background technique [0002] The Arctic is one of the focuses of competition among countries in the world. Taking the Arctic waterway can save a lot of ocean transportation resources, thus promoting the development of new concept ships such as Arctic shuttle tankers, icebreakers, and icebreaker container ships. New requirements include high strength, high toughness and seawater corrosion resistance in extremely cold environments. [0003] On June 19, 2017, the applicant applied for an invention patent application document titled high-strength, high-toughness corrosion-resistant steel that can be used in a low-temperature environment of -60°C and its production method. The applic...

AI Technical Summary

Problems solved by technology

The disadvantage is that the minimum service temperature of the prepared steel is only -60°C. At the same time, in order to further improve the corrosion resistance of the steel, it is necessary to add expensive alloying elements such as Zr and Ta, and to increase the strength of the steel, it is also necessary to add Cr elements.

Images