Preparation method for galvanized sheet hot-pressing stress hardening tubular part

Abstract

The invention discloses a preparation method for a galvanized sheet hot-pressing stress hardening tubular part. The preparation method comprises the following steps that A, the upper surface and the lower surface of a hot formed steel belt are coated with zinc layers with different thicknesses; B, galvanized hot-formed steel is subjected to split pipe rolling treatment to obtain an initial pipe, and the initial pipe is heated to a certain temperature for a certain time so as to be used for ensuring that the initial pipe is completely austenitized; C, a heated initial pipe is transferred into a mold, the two ends of the initial pipe are sealed, and the initial pipe is filled with compressed air with a certain pressure P; D, in the downward mold closing process of the mold, the appropriate feeding amount L of the two ends of the closed pipe is guaranteed under the action of a hydraulic driving device or a mold inclined wedge, and it is guaranteed that a coating at the inner side of the pipe is always in the pressure stress state in the axial direction of the pipe; and E, after forming, the mold keeps the pressure to achieve rapid heat exchange of a tubular plate between the molds so as to achieve quenching. According to the preparation method, the problem of LMIE cracking in the forming process of a galvanized sheet tubular part is solved, and the corrosion resistance of the tubular hot-formed part in the service process is improved.

Description

technical field [0001] The invention relates to the field of metal materials, in particular to a method for preparing a hot-pressed stress-hardened tubular part of a galvanized sheet. Background technique [0002] The light weight of the car effectively reduces the fuel consumption of the car and reduces the exhaust emission. Tubular parts with closed cross-section are widely used because of their better rigidity. The cold forming technology of pipe fittings mainly includes internal high pressure forming technology and low pressure upsetting forming technology; the hot forming technology of pipe fittings mainly includes hot air bulging forming and hot pier bulging forming technology. The materials used in the thermoforming technology for hot-formed steel pipe fittings are cold-rolled hot-formed steel (bare plate), and a large amount of scale will be produced during the heating process of the bare plate, and the inner and outer surfaces of the formed pipe fittings contain sc...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for preparing hot-pressed stress-hardened tubular parts of galvanized sheet, which solves the problem of LMIE cracking during the forming process of galvanized sheet tubular parts, and improves the corrosion resistance of tubular hot-formed parts during service sex

Images