A hot stamping forming method for zinc-based coated steel sheet or steel strip

Abstract

The invention relates to a hot-stamping forming method for a zinc plating steel plate or a steel strip. According to the hot-stamping forming method, the steel plate or the steel strip is conveyed into a vertical heating annealing furnace, the temperature is kept for a certain time, the steel plate is completely austenitized, a pre-cooling device is used when the steel plate leaves the annealing furnace, the steel plate is cooled to 650-700 DEG C at the cooling rate higher than 30 DEG C / s, then blanking is performed according to the part shape and size, then the steel plate is quickly transferred into a mold for hot-stamping forming, the steel plate is hardened at the speed higher than 30 DEG C / s, and the hot-stamping forming temperature is kept between 400 DEG C and 650 DEG C. Base plate cracks caused by partial stress and liquid metal embrittlement (LME) can be avoided, and the method is used for solving the problem that the base plate cracks cannot be avoided for existing zinc-based hot-stamping formed steel.

Description

Technical field [0001] The invention relates to the field of metal materials and is mainly applicable to the field of forming thin steel plates for automobile bodies. It is a forming method of hot stamping steel plates and steel strips and is mainly used in the manufacture of automobile B-pillars, door anti-collision beams, bumpers and other structural components. Background technique [0002] "Lightweighting" of automobiles can directly reduce emissions and reduce fuel consumption, which is the development goal of today's automobile manufacturing industry. The application of high-strength steel and ultra-high strength has become one of the mainstream development trends in the field of automobile manufacturing. However, ultra-high-strength steel plates are prone to problems such as poor shape, high processing load, and large rebound during cold processing, which affects ultra-high strength. The use of steel plates, therefore hot stamping is an important way to achieve ultra-...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a hot stamping forming method of zinc-based coated steel sheet or steel strip. Blanking is carried out, and finally hot stamping and in-mold quenching are carried out. The forming temperature range is 400-650°C, which can avoid substrate cracks caused by local stress and LME, and is used to solve the problem that current hot stamping forming steel cannot avoid substrate cracks.

Images