Due to the high-strength structural steel pipe is formed of high strength steel having a large moment of inertia and flexural modulus, in particular on the requirements of the application due to the need for cold bending processing after the pre-punched, the material would be formed on the surface roughness and the size of the edge material differences, thus requiring the class of high-strength structural steel design of cold-formed hole need more lateral positioning device designed to pass reasonable, rational arrangement of the roll gap, to ensure that every road pass into the material and no deviation eliminate the effects of possible differences in surface flatness and material dimensions on the edge of the subsequent cold forming shapes; the other outstanding features are: high-strength structural steel shaped rebound phenomenon is more serious, rebound cause arc edge must rely to correct cornering and over-angled more difficult to master, amendments need to be adjusted in the production process of debugging.
Need more forming passes. In cold roll forming process for bending the main process, in addition to local products have a slight thinning of the bending angle, the thickness of the deformation of the material in the molding process is assumed unchanged; in pass design, pay attention to the rational allocation of deformation volume, especially in the first, followed by a few, the deformation is not easy to be too large. Also you can use the corner roller and side roller on the pre-bent profile, so that the neutral line and the neutral line of the profile section and finished profiles coincide, so that the force balance of the vertical profiles suffer, thereby avoiding buckling. If you find that in the process of buckling, can increase the portion of the roll according to the actual situation, with particular attention to the back of a few. Others, such as using a leveler straightening, change the frame spacing, using rollers, adjust the movements of the roll gap and other measures can reduce or eliminate the longitudinal bending.
Note that, by adjusting the roll gap of the vehicles to reduce the longitudinal bending job requires skilled technicians. Cold roll speed control and adjusting of the pressure of the forming roll need to be right, to minimize repetitive bending fatigue crack cold-formed and properly lubricated and cooled, further reducing thermal stress cracks, and control the bend radius, bend radius that is not too is small, otherwise the product surface is easy to crack, for cold forming high-strength plate after the cold bending process ductile fracture phenomenon appears, in order to satisfy the structural design requirements, it is recommended in the context of optimizing the sectional shape designed to meet the mechanical requirements of the material, such as increasing the bending corner radius, reduce or increase the cross-sectional shape of the cold-angled handle, etc. is also an effective method.
Post time: Sep-29-2019