Problems and Countermeasures Analysis of Deep Drawing of Stainless Steel Sheet
Deep drawing technology is one of the most important metal forming processes in the automotive industry, especially for vehicles with metal surface forms. Stainless steel deep drawing can be used in many parts such as bumper centering plate, mesa, bonnet and so on. The use of stainless steel sheets will bring greater technological progress in the production process. However, deep drawing is one of the processing methods for cold working of metals, and the ever-increasing demand for complex shapes and sizes has led to various processing problems, such as wrinkling and tearing, which are difficult to solve. In order to analyze the problems encountered in deep drawing of stainless steel sheets and how to solve them, processes and countermeasures of deep drawing of stainless steel sheets are summarized as follows.
Process of deep drawing of stainless steel sheet
Deep drawing process is a forming technique to make a stamping part with a certain shape and size by applying a specific pressure on the blank. The process of deep drawing stainless steel sheet includes several steps: blanking→levelling→pre-drawing→forming→ trimming→checking→unloading.
First, the blank is cut from the stainless steel sheet according to the drawing requirement. Then, the blank is leveled. The leveling accuracy directly affects the drawing quality, including the accuracy of the drawing box and the drawing depth. If there is no leveling or the accuracy is not enough, it will affect the forming quality of the part.
The third step is pre-drawing. The purpose of pre-drawing is to make the parts enter the forming stage easier. Sometimes, people use a material called a pre-drawing wall to pre-draw the product before the forming stage. It helps to fix the product, give a better angle to the product and resist the tension force. Then, in the forming stage, the temperature of the part and the blank will rise, which makes its hardness and tensile strength lower, so that it is easier to form.
Next, in the forming stage, the pre-drawn wall will be pushed into the cavity, and the blank will be formed at the same time. The accuracy of the pre-drawing should be checked before the forming stage is started. Then, the trimming stage is carried out to remove the excess material outside the box corner. The last step is checking. After checking, the finished product can be unloaded from the mould.
Problems of deep drawing of stainless steel sheet
In the deep drawing of stainless steel sheets, there are three main problems: wrinkling, tearing and deformation.
Wrinkling is the most common problem in deep drawing. This leads to the deviation of accuracy and the increase of surface roughness of the work piece, which affects the quality of the finished product. The possible causes of this problem are poor communication between the blank and the die, too much lubricant, too high lubrication temperature, incorrect die design and excessive pre-drawing.
Tearing is also a common problem during deep drawing. The possible reasons are that the blank has larger than anticipated drawing area and abrupt drawing ratio, the drawing force is greater than anticipated, the temperature of the blank and die is too high, too much lubricant, incorrect position and wrong die design.
Deformation is also a common problem in deep drawing. Possible causes are irregular lower die, wrong springback setting, incorrect position of the blank and inappropriate die design.
Countermeasures of deep drawing of stainless steel sheet
In order to solve the problems encountered in deep drawing of stainless steel sheets, the following countermeasures should be taken.
First, the lubrication system should be improved. Lubricant should be evenly applied to the blank and die surfaces, and the lubrication temperature should be properly controlled.
Second, proper pre-drawing parameters should be selected. The pre-drawing step should be properly controlled in order to make a good forming effect.
Third, die design should also be improved. Die design should be improved scientifically, taking into consideration the size and shape of the object.
Fourth, the stamping process should be optimized. The stamping process should be optimized and fixed in order to reduce the strain during stamping and improve the forming effect.
Finally, the position of the blank should be correctly adjusted. The blank should be correctly adjusted to the bottom die in order to get the optimal drawing effect.
Conclusion
Deep drawing is an important technology and is widely used in the automotive industry. In order to ensure the production quality of stainless steel sheet deep drawing, the countermeasures mentioned above should be taken. With the improvement of deep drawing technology, the accuracy and surface roughness of stainless steel sheet deep drawing will be improved, and the life and usability of the product will be extended.
