Weak deoxidized q420mpa grade marine corrosion resistant steel and production method

By designing and optimizing the chemical composition of low C, high P, and high O, and adding elements such as Mn, Cu, Ni, Nb, Ti, Ce, and La, a ferrite + pearlite + bainite structure is formed. This solves the problems of high cost and reduced weldability of existing marine climate corrosion resistant steel alloys, and achieves improved high strength, low temperature toughness, and marine climate corrosion resistance.

CN118854160BActive Publication Date: 2026-06-02武汉钢铁有限公司
View PDF 5 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
武汉钢铁有限公司
Filing Date
2024-07-15
Publication Date
2026-06-02

AI Technical Summary

Technical Problem

Existing marine-resistant corrosion-resistant steel alloys are costly and have reduced weldability, making them unsuitable for use in extremely cold sea areas.

Method used

The chemical composition is designed with low C, high P, and high O, with the addition of elements such as Mn, Cu, Ni, Nb, Ti, Ce, and La, and the S content is controlled to form a ferrite + pearlite + bainite microstructure. Through optimized smelting and rolling processes, the yield strength is ensured to be ≥410MPa, tensile strength to be ≥550MPa, elongation after fracture to be ≥27%, impact energy at -60℃ to be ≥170J, and annual corrosion rate to be ≤1.3mm/y.

Benefits of technology

It achieves a significant reduction in alloy costs while ensuring strength and toughness, and improves the low-temperature toughness and resistance to marine climate corrosion of steel plates, making them suitable for extremely cold marine environments.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN118854160B_ABST
    Figure CN118854160B_ABST
Patent Text Reader

Abstract

A weakly deoxidized Q420MPa grade marine climate corrosion resistant steel, its composition and wt% are as follows: C: 0.05-0.15%, Si: 0.10-0.30%, Mn: 1.00-1.70%, P: 0.050-0.100%, S≤0.002%, Cu: 0.15-0.35%, Ni: 0.10-0.30%, Nb: 0.020-0.050%, Ti: 0.005-0.020%, O: 0. 0.010~0.025%, 0.020%≤Ce+La≤0.050%, 10%≤Si / O≤20%, 5%≤Mn / Si≤10%, CEV≤0.45, CEV=C+Mn / 6+(Cr+Mo+V) / 5+(Ni+Cu) / 15; Production process: After desulfurization of molten iron, it is smelted in a conventional converter; after casting, the billet is heated; high-pressure water descaling; rough rolling; finish rolling; cooling to coiling temperature; coiling; and conventional subsequent processes. This invention achieves a stable ferrite + pearlite + bainite microstructure by ensuring a yield strength ≥410MPa, tensile strength ≥550MPa, and elongation after fracture ≥27%, using a low C, high P, and high O composition, adding certain amounts of Mn, Cu, Ni, Nb, Ti, Ce, La, etc., and achieving a low-temperature impact energy of -60℃ ≥170J and an annual corrosion rate of ≤1.3mm / y in marine climates.
Need to check novelty before this filing date? Find Prior Art

Citation Information

Patent Citations

  • Seawater corrosion-resistant steel pipe and manufacturing method thereof

    CN104131232B

  • Seawater-corrosion-resistant steel and manufacturing method thereof

    CN106756593A

  • A seawater corrosion resistant steel plate and its production method

    CN110157982B

  • Ti-containing seawater corrosion resistant steel strip and preparation method thereof

    CN106498288A

  • Weakly deoxidized Q355-grade seawater corrosion resistant steel and manufacturing method thereof

    CN116837279A