The classification of the packaging steel strip of thinning drawing profile

The classification of the packaging steel strip thinning drawing profile thinning drawing can be divided into two ways: ( 1) Wall thickness thinning, inner diameter is not significantly reduced ( Billet diameter slightly larger, facilitate punch smoothly inserted after the procedure) 。 This is the production in this way, this is the focus of this chapter, with the way to dance in front of the workpiece thinning drawing, using ordinary drawing method make the billet diameter slightly larger than the workpiece diameter, then carries on the thinning drawing. ( 2) Wall thickness thinning, inner diameter narrow. Is in all thinning drawing process, all in accordance with the provisions, the deformation degree, make narrow diameter and wall thickness thinning, finally reach the required shape and size, because the way in the process of drawing deformation and stress is complex, easy to cause the workpiece is broken, and therefore do not usually use. Thinning drawing compared with the general drawing, has the following characteristics: ( 1) Thinning delay, material deformation zone is in the concave die hole taper part range of metal and force transmission area is has been pulled out from the concave to touch the sidewalls of the thickness for the t1 parts and the thickness of the bottom of the t0. ( 2) Deformation area of metal, mainly in the axial tension and compression of the other two to three to the stress state, namely by the convex molding pressure and the axial tensile stress, punch and die materials produced by the radial compressive stress and due to the mutual extrusion between the material and the tangential compressive stress. Strain state is produced in the axial elongation deformation, and tangential compressive deformation in the thickness direction. ( 3) In the process of thinning drawing, due to the deformation of the material is under a three-way stress state resulting cold work hardening phenomenon, cause metal grain fine, strength increase. ( 4) Thinning drawing without wrinkling problem, therefore don't need to use blank holder device, can be conducted on single action press deep drawing, the mold structure is simple and low cost. ( 5) In a press trip, if use for thinning in applying multilayer combination concave die, larger deformation degree can be obtained. Can be done in a press trip, a general drawing and two thinning drawing process. ( 6) Due to the friction in the process of drawing, so higher requirements for lubrication and mould materials.