Stainless steel stamping parts using materials and production process considerations
Analysis of materials used for stainless steel stamping parts
A. Smooth surface, no spot, no scar, no abrasion, no surface cracks, etc. Precision stamping parts processing plant all surface shortcomings will remain on the surface of the finished product workpiece, cracking shortcomings in the whole process of bending, deep drawing, forming, etc. is likely to expand to deep and wide, resulting in scrap.
Second, the uniform tensile strength is good. Compressive strength test, the test piece gradually occurs fine neck condition before the tensile strength is called uniform tensile strength. In the deep drawing, the deformation of all areas of the plate material can not exceed the proportional widening of the raw material, or it will occur disproportionate deformation.
Third, the thickness is accurate and proportional. Stamping processing die shell high precision, small gaps, and thin and thick plate material will enhance the exchange of deformation force, and lead to card material, and even the concave die expansion crack; plate material is too thin will endanger the quality of manufactured products, in deep drawing and even cracking.
Fourth, the cold hardening is low. Cold deformation after the emergence of cold hardening will enhance the deformation resistance of the material, making it difficult to deform again, so the general choice of the low hardness index value of the furniture plate. But the high value of the hardness index of the plastic deformation of the material is good (i.e. plastic deformation is more proportional), not easy to occur reversible pulling crack.
V. Homogeneous tensile strength, no obvious specificity. Various kinds of customized sheet metal processing (see plastic deformation of sheet material in the whole process of stamping processing such as deep drawing, reverse edge, expansion, etc., because there is a sequence in the generation of each direction of compromise, the amount of plastic deformation is not consistent, which will cause disproportionate deformation and make the molding inaccurate and lead to residual products or scrap.
Sixth, low yield-to-strong ratio. The ratio between the strength limit and yield limit of the raw material of the precision sheet metal processing factory is called the yield strength ratio. A low yield strength ratio can not only reduce the deformation resistance, but also reduce the tendency of wrinkling during deep drawing, reduce the rebound force after bending, and improve the precision of bending parts.
Compared with aluminum alloy profiles, stainless steel material hardness and compressive strength are relatively good, in the production process should pay attention to the following issues.
First, the selection of CNC blades
Stainless steel hardness is high, the depletion of the mold shell wound will be relatively large, and therefore in the selection of CNC blades to be based on the hardness of stainless steel materials to do the suitable selection.
Second, the heat treatment process
Much stainless steel stamping processing Lashin parts will appear better hardness regulations, but because the harder the raw material, the greater the difficulty factor of Lashin, sometimes according to the forming and then heat treatment process to do the hardness regulations, but the heat treatment process after the product workpiece is easy to produce deformation, need to be in the stamping die sufficient consideration of deformation variables.
III. Rebound deformation of raw materials
Metal materials will be rebounded after Lashin forming, because the hardness of stainless steel is good, and the rebound ratio of raw materials of stainless steel hardware stamping parts is large, when designing the program forming die, it is necessary to estimate the rebound amount of raw materials and try to avoid the specification problems caused by the rebound of raw materials.
The strength test of hardware stamping parts is usually carried out by Rockwell hardness tester, but there are restrictions for small and medium-sized stamping parts with complex appearances. The fundamental reason is that it can be used to test small flat drawings, so it cannot be tested on a general desktop all-in-one Rockwell hardness tester. The dimensional accuracy of hardware stamping is the difference between the specific dimensions of the stamping and the basic dimensions. The smaller the difference, the higher the dimensional accuracy of the hardware stamping part. The appearance of deviation is the direct cause of dimensional accuracy when reducing hardware stamping parts, while the deviation of hardware stamping parts' dimensions is generated by several elements.
It is confirmed by analysis that the manufacturing accuracy of the convex and concave die of hardware stamping parts; the gap of the convex and concave die; the ductility response of the raw material after the stamping process; the unintentional elements in the production process, such as the accurate positioning prohibition and the unstable characteristics of the raw material, are all causes of the dimensional deviation of hardware stamping gold. There is also about the surface quality of hardware stamping parts, under normal circumstances can not be higher than the surface quality of its raw materials, otherwise, the process of metal stamping parts processing production processing needs to enhance the back process, which will also prompt the product cost of stamping parts with the rise. From the dimensional deviation and surface quality, the dimensional accuracy of hardware stamping parts can be divided into two categories: high precision and common.
