Manufacturing method of age-hardened thin-strip casting low-carbon microalloyed steel strip

Abstract

The invention discloses a manufacturing method of an age-hardened thin-strip casting low-carbon microalloyed steel strip. The method comprises the following steps: 1) casting a cast strip with thickness of 1-5mm in a dual-roller continuous casting machine, wherein the weight percents of the components are as follows: 0.01-0.25% of C, not more than 0.4% of Si, 0.6-2.0% of Mn, not more than 0.015% of P, not more than 0.01% of S, and not more than 0.012% of N; furthermore, the cast strip further comprises at least one of Nb, V, Ti, and Mo in the following weight percent: 0.005-0.1% of Nb, 0.005-0.1% of V, 0.005-0.1% of Ti, and 0.05-0.5% of Mo, and the balance of Fe and unavoidable impurities; 2) cooling the cast strip, wherein the cooling rate is more than 20 DEG C / s; 3) hot-rolling at 1050-1250 DEG C, wherein the reduction rate is 20-50%, and the deformation rate is more than 20s-1; 4) cooling, wherein the cooling rate is 10-80 DEG C / s; 5) reeling at 550-700 DEG C; 6) performing age-hardening treatment, wherein the age-hardening temperature is 500-800 DEG C, and the heating time is 0.1-30 minutes. The austenite online recrystallization of the cast strip after hot-rolling is realized, the microstructure of the obtained steel strip is composed of fine polygonal ferrite and a pearlite, the structure comprises nanoscale precipitation such niobium carbonitride, and the high strength and extensibility are obtained.

Description

technical field [0001] The invention relates to the field of thin strip continuous casting products manufacturing, in particular to a method for manufacturing age-hardened thin strip continuous casting low-carbon microalloy steel strips. With excellent strong-plastic matching, the microstructure of the steel strip is mainly composed of fine polygonal ferrite and pearlite, and the structure contains nanoscale precipitates such as niobium carbonitride. 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 costs, resulting in high production costs. ...

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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