Aluminum-plated steel plate with tensile strength of 1800 MPa, manufacturing method thereof and hot forming part

Abstract

The invention discloses an aluminum-plated steel plate with tensile strength of 1800 MPa, a manufacturing method thereof and a hot forming part. The aluminum-plated steel plate comprises a base plateand a plating layer; the base plate comprises the following chemical components including, by weight, 0.25%-0.35% of C, 1.0%-1.5% of Si, 0.8%-3.0% of Mn, less than or equal to 0.05% of P, less than orequal to 0.05% of S, less than or equal to 0.10% of Al, 0-1.0% of Cr, less than or equal to 0.05% of Mo, less than or equal to 0.01% of N, 0.05%-0.10% of the sum of Nb and V and the balance Fe and unavoidable impurities; a plating solution for forming the plating layer comprises 3.0%-6.0% of Si, 0.5%-2.5% of any one or more of Sn, Cu and Mo and the balance Al and inevitable impurities; the steelplate is applied to manufacturing the hot forming part, after materials are subjected to hot forming, the performance requirement that the tensile strength is larger than or equal to 1800 MPa is met,and the excellent comprehensive mechanical property is achieved; and when the steel plate is used for hot forming part, the uneven appearance formed after electrophoresis of a traditional aluminum-silicon steel plate can be eliminated, and the adhesive force and the corrosion resistance after electrophoretic coating are improved.

Description

technical field [0001] The invention belongs to the technical field of hot-formed steel, and in particular relates to an aluminized steel plate with a tensile strength of 1800 MPa, a manufacturing method thereof, and a hot-formed part. Background technique [0002] In recent years, the strict laws and regulations on energy saving and emission reduction have put forward higher requirements for the lightweight of the car body. In order to reduce the weight of the car body while maintaining safety performance, high-strength parts are widely used in the manufacture of car bodies. Due to the springback effect of cold-formed ultra-high-strength steel in the stamping process, the application of ultra-high-strength steel in car body is limited. Thermoforming technology has been widely used and popularized due to its high dimensional accuracy, no springback effect, and high strength level. [0003] In the hot stamping process, the use of uncoated plates requires a protective atmosp...

AI Technical Summary

Problems solved by technology

[0004] However, the Al-Si coating is in contact with the air during the thermoforming process to form an aluminum-silicon oxide film covering the surface. This layer of oxide cannot be dissolved by phosphoric acid, so that the phosphating film cannot be formed.

Therefore, Al-Si coated hot-formed steel parts cannot form a good-quality phosphating film to ensure the adhesion and corrosion resistance of the electrophoretic paint layer when they are loaded and painted.

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