What kind of Cutting fluid should CNC machine cast iron?
August 04, 2023
Some people think that cast iron contains graphite, and its CNC processing does not need Cutting fluid. Today, let's take a look at whether we need to add Cutting fluid for CNC processing of cast iron? If necessary, what kind of Cutting fluid should be added?
Do you need Cutting fluid for CNC machining of cast iron? When cast iron is processed by CNC, it will be affected by Thermal expansion, which will cause considerable wear to the tool. Therefore, Cutting fluid is required for CNC machining of cast iron. What kind of Cutting fluid should be added when CNC machining cast iron? 01. Cast iron is very easy to rust during CNC machining, and the use of ordinary Cutting fluid will not have a good machining effect. The selection of cast iron Cutting fluid must meet the requirements of its cutting performance and service performance. 02. During the processing of cast iron, it is easy to produce metal chips, and the cutting force and cutting heat are concentrated near the cutting edge and the tool tip. The rear tool face is easy to wear, which will cause tool failure. Therefore, cast iron Cutting fluid should have good cooling and cleaning performance. 03. The structure of cast iron is very uneven, and it contains flake graphite and sand inclusion inside. It is easy to form micro batteries and quickly corrode in the presence of water, so the requirements for rust prevention of Cutting fluid are high.
When cutting cast iron, a large number of small cuts, including iron powder and graphite powder, are produced. Iron powder is easy to react with some chemicals in Cutting fluid and generate iron oxide, which will make Cutting fluid red brown and then deteriorate. Graphite powder has hydrophobic and lipophilic properties, making it easy to be soaked by oil. When oil-bearing emulsified Cutting fluid and microemulsion Cutting fluid are used, the graphite component in the chip will absorb the oil in Cutting fluid, resulting in the reduction of the actual oil content of Cutting fluid and the decline of Cutting fluid performance. Therefore, Cutting fluid is required to have a good sedimentation effect on chips. 05. The stability of cast iron Cutting fluid, no irritating smell, no damage to workers' skin, and good environmental protection performance should also be considered. What should be paid attention to when using cast iron Cutting fluid? According to relevant experience, we should also pay attention to the following points when using cast iron Cutting fluid: 01. Before replacing cast iron Cutting fluid, the water tank, pipeline and other parts contacting with Cutting fluid shall be thoroughly cleaned. 02. The concentration of use can be selected based on the product instructions and processing technology. For processing with high requirements for lubrication, smoothness, and rust prevention, the upper limit concentration or higher concentration should be taken, and the original solution and water should be added regularly during use. 03. Tap water or deionized water with good quality shall be selected for dilution of Cutting fluid. 04. Accurately master the concentration of Cutting fluid, and use a refractometer to control it, rather than relying on personal experience. The performance of Cutting fluid is reduced. 05. Regularly test the concentration and pH value of Cutting fluid. It is recommended to use special Cutting fluid for cast iron, which can not only meet the rust prevention, cooling and cleaning performance required for cast iron, but also has good sedimentation and excellent foam inhibition. The working fluid takes away less and does not contain mineral oil, so it is difficult to breed bacteria, effectively inhibit odor, and significantly improve the service life of working fluid and reduce the cost of working fluid.
