How to ensure the best use of cutting fluid or effectively extend its service life?
April 23, 2022
The usual practice is to choose a high-quality cutting fluid. Under the premise of correct selection, it is actually necessary to do daily maintenance and maintenance of cutting fluid. 1. Rational use of cutting fluid Reasonable use of metal cutting fluid can effectively reduce cutting force, cutting temperature and thermal deformation of processing system, which can not only ensure the processing quality of workpiece, but also prolong tool life and reduce processing cost. The main functions of metal cutting fluids in mechanical removal processing are cooling, lubrication, cleaning and rust prevention. The effect of the cutting fluid depends not only on the various properties of the cutting fluid itself, but also on the processing requirements, workpiece materials, tool materials and processing methods.
(1) Choose according to processing requirements During rough machining, the cutting amount is large and a large amount of cutting heat is generated. In order to reduce the cutting temperature, a water-based cutting fluid with good cooling performance should be used at this time. When finishing, the workpiece is required to obtain the best surface quality and small surface roughness value, so cutting oil should be used. (2) To correspond to different processing methods In contemporary machining, cutting methods are varied. For example, turning, milling and drilling usually require high-efficiency processing, so water-based cutting fluids should be used; while broaching and gear cutting, more expensive and complex tools must be used to ensure processing quality and long-term use of the tool. Therefore, it is best to use oil-based cutting fluid. (3) It should be selected according to the different materials of the workpiece and the tool Different materials of tools and workpieces have different high temperature resistance, machinability, hardness, etc., and different cutting fluids should be selected at this time. For example, when machining workpieces with low hardness such as gears, a cutting fluid with a higher viscosity should be used to prevent scratches on the surface of the gears; while cutting hard-to-machine materials such as stainless steel, extreme pressure cutting oil or extreme pressure emulsion should be used. . (4) To choose according to the characteristics of the machine tool itself For some high-efficiency and valuable equipment, from the perspective of maintenance, oil-based cutting fluids with stable physical and chemical properties should be used to prevent metal parts from corroding, rusting, and obstacles in the moving parts of moving parts. However, it is generally not suitable to use oil-based cutting fluid for some open machine tools, so as to avoid a large amount of volatilization and dissipation of the cutting oil. 2. Daily maintenance and maintenance of Metal Working Fluid As daily maintenance, the first thing to think about is the control of product concentration. Any brand or model of cutting fluid has the manufacturer's recommended concentration range, which is not only related to the cutting fluid itself, but also directly related to the processing technology. It is recommended that the concentration be strictly controlled within the recommended range during routine maintenance. For processes with high requirements for finishing or processing quality, an appropriate increase of 1%-2% on the basis of the manufacturer's recommended range can reduce fluctuations in concentration. The impact of the processing quality and tool life, but also effectively prolong the life of cutting fluid. However, the actual maintenance cost is not as much as imagined. The reason is that most of the evaporated water during processing is water, so the rehydration concentration will be much lower than the recommended concentration under normal circumstances. How to reduce the fluctuation of cutting fluid concentration? There are the following measures: First of all, it 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%-80% of the liquid tank capacity; the liquid level of a single machine should not be lower than 80% of the liquid tank capacity.
(2) Set the target value, that is, the median value of the concentration range; if it is lower than this value, fluid should be added;
(3) When adding liquid, it is recommended to use a mixer. If there is no mixer, it should be added at the maximum flow rate when adding liquid, so that the original solution can be dispersed as soon as possible; Secondly, it is to monitor the pH value of the cutting fluid, which is like the body temperature, too low or too high is unfavorable. Generally speaking, the optimal range of cutting fluid is between 8.8-9.5. However, the problem of cutting fluid is more "low fever", especially in summer when the operating rate is not high, the probability of pH reduction will be more. What if the pH value drops? (1) It is still within the controllable range, the concentration can be appropriately increased by 1-2%, and the management of oil slicks and regular circulation can be strengthened;
(2) When the pH value is between 8.5 and 8.8, an appropriate amount of the pH enhancer specified by the manufacturer can be added, and the microbial content can be detected;
(3) When the pH is less than 8.5, the cutting fluid will be accompanied by peculiar smell. At this time, it is necessary to sterilize it immediately. At the same time, it is necessary to contact the cutting fluid supplier to find out the reasons and formulate a reasonable solution.
