Hot rolling strip steel for high-strength cold forming welding structures and manufacturing method thereof

Abstract

The invention provides a hot rolling strip steel for high-strength cold forming welding structures and a manufacturing method thereof. The hot rolling strip steel comprises the following components: 0.055-0.09% of C, 0.05-0.50% of Si, 1.50-1.90% of Mn, 0.035-0.07% of Nb, 0.06-0.13% of Ti, 0.05-1.0% of Cr, 0.010-0.070% of Als and the balance of Fe and other unavoidable impurities. The manufacturing method comprises the steps of smelting, refining, continuous casting and rolling; heating up to 1150-1250 DEG C before rolling; rolling is controlled by two stages; rough rolling ending temperature is more than 1020 DEG C, finish rolling beginning temperature is less than 1040 DEG C, and finish rolling ending temperature is controlled to 820-920 DEG C; quick cooling is carried out after rolling; and reeling temperature is 520-620 DEG C. The hot rolling strip steel contains few C and more Ti and adds a proper amount of Cr and Nb; by the composite invigorating effect of elements, such as Cr, Nb and Ti, no noble elements, such as Mo, Ni, Cu, V and the like are added; steel types have favourable toughness, plasticity and welding property and convenient production operation and do not need heat treatment technology, such as tempering or conditioning and the like while improving strength.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and in particular relates to a hot-rolled steel strip for high-strength cold-formed welded structures and a manufacturing method thereof. Background technique [0002] Steel with high strength and excellent comprehensive mechanical properties to reduce its own weight, greatly improve its carrying capacity, and increase the economic benefits of logistics enterprises. At the same time, it can also greatly reduce fuel consumption and transportation costs during empty trips. Moreover, the use of high-strength steel can reduce the amount of steel used, which will be of great benefit to environmental protection, energy saving and saving raw materials. [0003] Although the technology related to high-strength cold-formed welding steel has been published in the literature, there is a problem of high production cost. Such as: [0004] The Chinese patent application number 200610116562.8 provide...

AI Technical Summary

Problems solved by technology

Its disadvantages are: in order to improve the strength of the steel, a higher content of precious alloy elements is added to the composition design, which not only increases the cost of the steel, but also has an adverse effect on the welding performance of the steel, and the yield strength of the steel is Can only reach ≥500N / mm 2 , Tensile strength reaches 590N / mm 2 above

[0006] The publication number of Nippon Steel’s application in China is CN1639371A, and the patent titled "Weather-resistant high-strength steel plate with excellent bending workability and its manufacturing method" has the disadvantage that more alloying elements are added to the steel, such as Ni The content of Ti is up to 2.0%, and the content of Ti is up to 0.2%. Higher alloying elements not only cause a substantial increase in cost, but also increase the difficulty of production. There are many production processes and complex production operations.

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