Manufacturing method of thin-strip continuous casting low-carbon micro-alloy high-strength steel strip

Abstract

The invention discloses a manufacturing method of a thin-strip continuous casting low-carbon micro-alloy high-strength steel strip. The manufacturing method comprises the following steps of: (1) smelting and performing thin-strip continuous casting, wherein the steel strip comprises the following chemical components in percentage by weight: 0.01-0.25 percent of C, less than or equal to 0.4 percent of Si, 0.6-2.0 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.01 percent of S, less than or equal to 0.006 percent of N, less than or equal to 0.008 percent of O, 0.0005-0.004 percent of B, 0.005-0.1 percent of Nb, 0.005-0.1 percent of V, 0.005-0.1 percent of Ti, 0.05-0.5 percent of Mo and the balance of Fe and inevitable impurities, and casting a cast strip with the thickness of 1-5mm in a double-roll continuous casting machine; (2) cooling the cast strip, wherein the cooling rate is greater than 20 DEG C / s; (3) performing hot rolling, wherein the hot rolling temperature is 1,050-1,250 DEG C, the reduction rate is 20-50 percent, and the deformation rate is greater than 20s<-1>; and (4) cooling and rolling. According to the manufacturing method, austenite is re-crystallized on line after the hot rolling of the cast strip is realized, the austenite grains are thinned and the dimensional uniformity of the austenite grains is improved, meanwhile, the hardenability of the re-crystallized austenite is improved, and a more uniform structure of bainite and acicular ferrite is obtained, so that the product simultaneously has high strength and extensibility.

Description

technical field [0001] The present invention relates to a thin strip continuous casting process, in particular to a thin strip continuous casting low-carbon micro-alloy high-strength steel strip manufacturing method, the obtained high-strength steel strip has a yield strength of ≥340MPa, a tensile strength of ≥450MPa, and an elongation of ≥15%. With excellent strong-plastic matching, the microstructure of the obtained steel strip is mainly composed of uniform bainite and acicular ferrite. Background technique [0002] At present, the production of low-carbon high-strength thin-gauge steel strip products containing microalloying elements such as Nb, V, Ti, and Mo is mainly realized through traditional hot rolling and cold rolling processes. However, there are some problems in the production by traditional hot rolling or cold rolling process: [0003] First of all, the traditional process is long, high energy consumption, many units and equipment, and high infrastructure cost...

AI Technical Summary

Problems solved by technology

This not only increases the investment cost, but also significantly increases the floor area of ​​the thin strip continuous casting and rolling production line, reducing the advantages of the production line

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