A kind of weathering steel for 550mpa grade hot-rolled container with stable rust layer and production method

Abstract

A 550MPa grade hot-rolled container weathering steel with a stable rust layer, its components and wt% are: C: 0.05~0.08%, Si: 0.32~0.38%, Mn: 0.50~0.60%, Cr: 0.60~0.80 %, Cu: 0.32~0.40%, Mo: 0.10~0.18%, Nb: 0.05~0.07%, Ti: 0.01~0.02%, P not more than 0.020%, S≤0.005%. Production method: Smelted by converter, vacuum Ca treatment, casting billet; heating billet; rough rolling; finish rolling; laminar cooling with NaCl solution; natural cooling; stabilized rust layer treatment; coiling. Under the premise of ensuring the yield strength of the steel plate is 550~580MPa, the tensile strength is 620~650MPa, and the elongation rate is ≥20%, the present invention realizes the online formation of a dense and stable rust layer with a thickness of not less than 3µm on the steel plate surface, and exposes the corrosion rate in the atmospheric environment. No more than 0.035µm / a, no yellow rust flow phenomenon, and no need to use after painting, which improves the surface quality and production efficiency of the steel plate.

Description

technical field [0001] The invention relates to a container steel and a production method, in particular to a 550MPa grade hot-rolled container weathering steel with a stable rust layer and a production method. Background technique [0002] During atmospheric corrosion, the alloying elements in weathering steel can improve the structure and performance of the rust layer, form a dense protective rust layer, effectively block the infiltration and transmission of corrosive media, and inhibit the further occurrence of corrosion. Weathering steel has been widely used in the container industry. Although weathering steel has good corrosion resistance, it takes a long time to form a stable and dense protective rust layer on the surface of weathering steel in the natural environment, and weathering steel is the same as ordinary carbon steel in the initial stage when it is used in the open. Red rust will be generated, and the rust liquid will hang and scatter, polluting the surroundi...

AI Technical Summary

Problems solved by technology

Nowadays, the rust layer stabilization treatment technology has been applied to weathering steel products or structures, but all of them are processed offline, that is, the rust layer is manually coated on the surface of the steel plate offline, which is not only uneven in the coating layer, but also labor-intensive. The production efficiency is low and has a certain impact on the operator's body

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