Measures to Prevent White Points from Appearing in Deep Drawing
Deep drawing is a sheet metal forming process commonly used in metal forming industry. During the deep drawing process, defects can easily occur, which will cause great waste of materials and affect the later product quality. Among them, one of the defects that are easy to appear is the white point. The white point defect mainly occurs in the process of deep drawing of stainless steel sheet. In this paper, measures to prevent the occurrence of white points in stainless steel deep drawing are discussed.
First of all, it is necessary to pay attention to the selection of materials. Different processes have different requirements for the performance of stainless steel sheet. Before processing, it is necessary to understand the difference between the characteristics of the material used and the edge shape, and reasonably select the material performance to meet the requirement of deep drawing.
Secondly, choose suitable lubricants. The lubricant of deep drawing process is the key of stainless steel deep drawing, different kinds of lubricants have different effects on products. Generally speaking, water-soluble lubricant is more suitable for deep drawing process, because it can quickly cool and lubricate materials in the drawing process, it can prevent white point to a certain extent.
Thirdly, the surface improvement of stainless steel plates should be properly carried out. On the surface of stainless steel plates, rust, pits, scales and other foreign matter should be removed. If there are too many flaws, it will easily lead to micro cracks and then form white points in the deep drawing process.
In addition, the die groove should be designed reasonably. When designing the die, enough consideration should be taken to avoid excessive loads on the workpiece, so as to reduce the possibility of internal cracks or stress concentration at the corners, which is beneficial to prevent white point defect.
Finally, pay attention to the deep drawing speed. The speed of deep drawing should not be too fast, because if the conveyor speed is too fast, the lubricant will not have enough time to completely infiltrate into the surface of the product, resulting in insufficient lubrication of the product, which will increase its internal stress, resulting in white point defect.
In conclusion, in view of the defect of white point in the deep drawing process, corresponding measures should be taken according to the characteristics of the process and materials, so as to prevent the occurrence of white points in the deep drawing process.
