1. Stainless steel plate CNC bending machine processing points
Due to the high yield point and high hardness of the stainless steel itself, the cold work hardening effect is remarkable, and the characteristics of the stainless steel plate when bending are as follows:
1) Because the thermal conductivity is worse than ordinary low carbon steel, the elongation is low, resulting in a large deformation force;
2) Stainless steel sheets have a strong tendency to rebound when compared with carbon steel during bending;
3) The stainless steel plate has a lower elongation than the carbon steel, and the bending angle R of the workpiece is larger than that of the carbon steel when bending, otherwise there is a possibility of cracking;
4) Due to the high hardness of the stainless steel plate, the cold work hardening effect is remarkable. Therefore, when selecting the bending tool, the tool steel with heat treatment hardness of 60HRC or more should be selected, and the surface roughness should be one order of magnitude higher than that of the carbon steel bending tool.
According to the above characteristics, in general:
1. Under the unit size, the thicker the sheet, the greater the bending force required, and the margin of bending force should be larger when the bending equipment is selected as the thickness increases;
2. Under the unit size, the greater the tensile strength, the smaller the elongation, the greater the bending force required, and the larger the bending angle should be;
3. In the case of designing the thickness of the plate and the bending radius, according to experience, the unfolding size of a curved workpiece is the right angle and the two plate thicknesses are added and subtracted, which can fully meet the design accuracy requirements, and the expansion amount can be calculated according to the empirical formula. Simplify the calculation process and greatly improve production efficiency;
4. The greater the yield strength of the material, the greater the elastic recovery. In order to obtain the angle of 90 degrees of the bending member, the angle of the required pressing knife should be designed to be smaller. Compared with the same thickness of carbon steel, the stainless steel has a large bending angle. This point should pay special attention to the occurrence of crushing cracks and affect the strength of the workpiece.
2. Stainless steel rebound
The rebound of stainless steel is really troublesome. Related to many reasons
1. Hardness: The greater the hardness, the greater the rebound. Last time I used 301-EH material, the rebound was placed at 14 degrees. 2. Bending radius material thickness and material thickness ratio: the larger the ratio, the larger the rebound.
3. SUS301 rebounds more than SUS304. In the same situation, 304 is 2 degrees smaller than 301. In addition, Japan 301 is bigger than Taiwan's rebound.
4. There are also differences in molding methods. The rebound in one step is larger than the rebound in multiple moldings.
5. My customary practice is to correct after the test, how many degrees of change, and pay attention to the rebound of the rebound and radius rebound, the specific situation is analyzed.
Of course, if the technician's skill is good, he will misplace it to adjust, and then adjust the design to make corresponding changes. Generally, every time you move 5, try this. It depends on the skill and experience of the technician.
Three. Stainless steel plate CNC bending machine processing rebound solution
It is recommended to use the three-cylinder CNC bending machine to solve the rebound problem during the bending process. The straightness and angle of the three-cylinder CNC bending machine are more guaranteed.