Alkali and corrosion resistant anchor chain steel and its production method

Abstract

An alkali and corrosion resistant anchor chain steel comprises 0.27-0.33wt% of C, 0.15-0.55wt% of Si, 1.4-1.6wt% of Mn, 0.035wt% or less of P, 0.015wt% or less of S, 0.001-0.003wt% of B, 0.03-0.05wt% of V, 0.1-0.25wt% of Cu, 0.025-0.035wt% of Als, 0.1-0.25wt% of Ni and 0.001-0.007wt% of Ca. A production method of the anchor chain steel comprises the steps of molten iron desulphurization, converter smelting, argon blowing, LF furnace refining, RH furnace vacuum treatment, blank casting, natural pile cooling to room temperature, rough rolling, finish rolling, and air cooling to room temperature. The production method can improve the alkali resistance of steel by above 45%, allows the anchor chain steel to have a long service life under alkaline conditions, and reduces the alloy content without reducing the material performances in order to reduce the production cost; the obtained alkali resistant anchor chain steel has excellent weldability and plasticity; and a converter technology has a high energy / efficiency ratio.

Description

Technical field The invention relates to the technical field of production of low alloy steel, and is particularly suitable for a production method of alkali corrosion resistant anchor chain steel with a diameter of not more than 40 mm. Background technique Anchor chain is an important component in ships and marine engineering. It is a high-strength, high-tech product and is widely used in mooring positioning of large ships. The service conditions are harsh and long-term immersion in seawater, so not only high strength and good toughness are required, but also good seawater corrosion resistance and abrasion resistance are required. Anchor chain steel is the raw material used to make the chain, so its quality requirements are self-evident. When the anchor chain is used in the Dead Sea or other alkaline seas, it will face corrosion in an alkaline environment. The current research on the corrosion of anchor chain steel is mainly acidic seawater corrosion. There are few reports on...

AI Technical Summary

Problems solved by technology

This technology has the following problems: ⅰ carbon equivalent is high, which affects welding performance; ⅱ the production cost of electric furnace is higher than that of converter; Otherwise, the material will undergo structural transformation during placement, resulting in structural stress, resulting in internal cracks in the material; ⅳThe steel’s alkali resistance is similar to that of ordinary anchor chain steel in an alkaline environment

The disadvantage is that the chromium content is an element that is easy to segregate. The dendrite segregation generated during the solidification process affects the overall corrosion resistance. At the same time, the dendrite segregation is easy to produce a banded structure, and the banded structure will cause the mechanical properties of the steel to be directional. Reduce the transverse plasticity and toughness of the steel; in addition, the alkali resistance of the steel is similar to that of ordinary anchor chain steel in an alkaline environment

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