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How to extend the best use of cutting fluid?

Sep 20, 2019

To prolong the best use state of cutting fluid, in addition to selecting high quality cutting fluid, we also need to do a good job in the daily maintenance and maintenance of cutting fluid.
I. rational use of cutting fluid.
The rational use of metal cutting fluid can effectively reduce the cutting force, reduce the cutting temperature and reduce the thermal deformation of the machining system, which can not only ensure the machining quality of the workpiece, but also prolong the tool life and reduce the machining cost. The main functions of metal cutting fluid in machining are cooling, lubrication, cleaning and rust prevention. The effect of cutting fluid depends not only on the properties of cutting fluid itself, but also on machining requirements, workpiece materials, tool materials and machining methods.
1. It is necessary to select according to the processing requirements.
In rough machining, the cutting parameters are large, resulting in a lot of cutting heat. In order to reduce the cutting temperature, the water-based cutting fluid with good cooling performance should be selected. In finishing, the workpiece is required to obtain the best surface quality and small surface roughness value, so the cutting oil should be used.
2. Correspond to different processing methods.
In contemporary machining, there are a variety of cutting methods. For example, turning, milling and drilling usually require high efficiency, so water-based cutting fluid should be selected. When broaching and cutting teeth, it is necessary to use more expensive complex cutting tools, in order to ensure the machining quality and the tool has a long service life, so it is best to choose oil-based cutting fluid.
3. Choose according to the different materials of the workpiece and the tool.
Different materials of cutting tools and workpieces, their high temperature resistance, machinability, hardness and so on are different, at this time to choose different cutting fluid. For example, in machining lower hardness workpieces such as gears, cutting fluids with higher viscosity should be used to prevent scratches on the surface of gears, while cutting stainless steel and other difficult-to-machining materials should be selected as extreme pressure cutting oil or extreme pressure emulsion.
4. It should be selected according to the characteristics of the machine tool itself.
For some high efficiency and valuable equipment, from the point of view of maintenance, oil-based cutting fluid with stable physical and chemical properties should be selected to prevent metal parts from corrosion, rust, moving parts and so on. However, for some open machine tools, it is generally not suitable to use oil-based cutting fluid, so as not to dissipate a large amount of volatile cutting oil.
II.Daily maintenance and maintenance of metal working fluids.
As a daily maintenance, first of all, it is the control of product concentration, any brand or type of cutting fluid has the recommended concentration range, which is not only related to the cutting fluid itself, but also directly related to the processing technology. It is suggested that in the course of daily maintenance, the concentration should be strictly controlled within the recommended range, and the processes requiring high finishing or processing quality should be appropriately increased by 1%-2% on the basis of the recommended range. This can not only reduce the influence of machining quality and tool life caused by concentration fluctuation, but also effectively prolong the life of cutting fluid.
However, the actual maintenance cost is not as much as expected, because the vast majority of evaporation during processing is water, so under normal circumstances the rehydration concentration will be much lower than the recommended concentration.
How to reduce the fluctuation of cutting fluid concentration? There are the following measures:
The first step is the control of liquid level and concentration.
1. Maintain a reasonable liquid level, generally speaking, the liquid level of the centralized liquid supply system is controlled between 60% and 80% of the liquid tank capacity, and the liquid level of a single machine should not be less than 80% of the liquid tank capacity as far as possible.
2. Set the target value, that is, the median value of the concentration range; below this value, you should replenish the liquid.
3. When replenishing liquid, it is recommended to use the mixer. If there is no mixer, the liquid should be added to the maximum flow rate, so that the original liquid can be dispersed as soon as possible.
The second is to monitor the pH value of the cutting fluid, just as the body temperature is too low or too high. Generally speaking, the best range of cutting fluid is between 8.8 and 9.5, but the problem of cutting fluid is more "low fever", especially when the operating rate is not high in summer, the probability of pH reduction will be more.
What if the pH value is reduced?
1. Still within the controllable range, the concentration can be increased by 1-2%, and the management of oil slick and regular circulation can be strengthened.
2. When the pH value is between 8.5 and 8.8, an appropriate amount of pH improver specified by the manufacturer can be added, and the content of microorganism can be detected.
3. When pH < 8.5, sterilization should be carried out immediately. At the same time, measures should be taken to improve it.