What are the factors that affect the service life of forming tools?

Linear velocity has a great influence on tool life. If the linear speed is 20% higher than the specified linear speed of the sample, the tool life will be reduced to 1/2 of the original; If it is increased to 50%, the tool life will be only 1/5 of the original. To improve the service life of the tool, it is necessary to know the material and state of each type of workpiece to be machined and the linear speed range of the selected tool. The linear speed of the cutter is different, so it can be adjusted according to the specific conditions during processing to achieve an ideal effect. The data of linear speed in rough machining and finish machining are not consistent. The rough machining mainly focuses on allowance removal, and the linear speed is low; Finish machining is mainly to ensure dimensional accuracy and roughness, with high linear speed.
The manufacturer of the forming tool said that the cutting depth has less influence on the tool life than the linear speed. Each groove type has a relatively large cutting depth range. During rough machining, the cutting depth shall be increased as much as possible to ensure a large margin removal rate; When finishing, the cutting depth shall be as small as possible to ensure the dimensional accuracy and surface quality of the workpiece. However, the cutting depth shall not exceed the cutting range of the groove. If the cutting depth is too large, the tool cannot bear the cutting force, resulting in tool breakage; If the cutting depth is too small, the tool will only scrape and extrude on the workpiece surface, causing serious wear of the rear tool surface, thus reducing the tool life.
There are many reasons for vibration, including machine tool rigidity, tooling rigidity, workpiece rigidity, cutting parameters, tool groove type, tool tip arc radius, blade back angle, tool rod overhang length, etc., but the main reason is that the system rigidity is not enough to resist the cutting force during processing, resulting in the constant vibration of the tool on the workpiece surface during machining. The elimination or reduction of vibration shall be considered comprehensively. The tool life is greatly reduced.
During workpiece processing, we mainly consider the workpiece material, heat treatment requirements and whether intermittent processing is required. The blades for processing steel parts are not necessarily the same as those for processing cast iron, and the blades with processing hardness of HB215 and HRC62 are not necessarily the same; The blades for intermittent machining and continuous machining are not the same. Steel blade is used for processing steel parts, casting blade is used for processing castings, CBN blade is used for processing hardened steel, etc. For the same workpiece material, if it is processed continuously, a higher hardness blade can be used to improve the cutting speed of the workpiece, reduce the wear of the tool tip, and reduce the processing time; If it is intermittent processing, it is necessary to use a blade with better toughness, which can effectively reduce abnormal wear such as blade breakage, and improve the service life of the tool.
The manufacturer of the formed tool said that a large amount of heat will be generated during the use of the tool, which will greatly increase the temperature of the blade. When the tool is not processed or cooled with cooling water, the temperature of the blade will decrease. Therefore, the blade is always in a high temperature range, which makes the blade constantly expand and contract, causing the blade to have small cracks. As the use of the blade increases, the cracks will extend to other blades, leading to a reduction in the life of other blades.