Method and device for improving formability of tailor-welded steel plate

Abstract

The invention relates to a method and a device for improving the formability of a tailor-welded steel plate. The method is characterized in that a tailor-welded steel plate after welding is placed in a low-frequency alternating magnetic field to be subjected to magnetic field destressing treatment, the treatment time is 20 s to 300 s, the magnetic induction intensity of the low-frequency alternating magnetic field ensures that all base metals of the tailor-welded steel plate can reach a magnetic saturation state, the frequency of the low-frequency alternating magnetic field is 0.2 Hz to 10 Hz, and the welding direction of the tailor-welded steel plate is perpendicular to the direction of the low-frequency alternating magnetic field. The device comprises an iron core (9), an excitation coil winding (1), a variable velocity variable frequency (VVVF) device (10), an alternating current power supply (11) and a clamp (3) used for clamping the tailor-welded steel plate (6). Through the application of the method and the device, the welding residual stress of the tailor-welded steel plate can be reduced effectively, the formability of the tailor-welded steel plate is improved, the advantages of energy conservation and environmental protection are achieved, and meanwhile, various bad consequences caused by traditional high temperature tempering and destressing manners can be avoided.

Description

technical field [0001] The invention relates to the field of tailor-welded steel plates, and more specifically, to a method and device for improving the formability of tailor-welded steel plates. Background technique [0002] With the continuous improvement of automobile lightweight requirements, tailor-welded steel sheets, especially laser-tailored welded steel sheets, have been widely used in the manufacture of automobile panels. However, the stamping formability of tailor-welded steel plates is much lower than that of ordinary steel plates. Improving the formability of tailor-welded steel plates has important scientific research value and engineering practice significance. [0003] An important reason for the decline in the formability of tailor-welded steel plates is that there are drastic temperature changes in the steel plates during welding and subsequent cooling, which causes very large welding residual stress in the weld seam and heat-affected zone. The tailor-wel...

AI Technical Summary

Problems solved by technology

Elimination of welding residual stress through overall or partial high temperature tempering process may cause a series of problems such as metal oxidation at high temperature, energy waste and environmental pollution.

More importantly, in the case of large differences in the thermal expansion coefficients of the base metal on both sides of the weld seam of tailor-welded steel plates, it is likely to cause new internal stress after high-temperature tempering and cooling, resulting in a decrease in product dimensional accuracy and even introducing new potential hazards. factor

Images