To select metal cutting fluid, it is first necessary to select pure oil-based metal cutting fluid or water-soluble metal cutting fluid according to the process conditions and requirements of cutting. Usually we can choose according to the recommendation of the machine tool supplier; Secondly, it can also be selected according to conventional experience. For example, when high-speed steel tools are used for low-speed cutting, pure oil-based metal cutting fluid is usually used; when hard alloy tools are used for high-speed cutting, water-soluble metal cutting fluid is usually used; Pure oil-based metal cutting fluid (such as tapping, broaching of inner holes, etc.) is used when it is difficult to supply fluid or the cutting fluid is not easy to reach the cutting area. In other cases, water-soluble metal cutting fluid can be used.
In short, the specific cutting fluid type shall be selected according to the specific cutting conditions and requirements, the different characteristics of pure oil-based metal cutting fluid and water-soluble metal cutting fluid, and the different actual conditions of each plant, such as the ventilation conditions of the workshop, the waste liquid treatment capacity and the use of cutting fluid in the previous and subsequent processes.
Secondly, after selecting the type of cutting fluid, the type of cutting fluid should be preliminarily selected according to the cutting process, the material of the workpiece and the requirements for the machining accuracy and roughness of the workpiece. For example, when selecting the cutting fluid for grinding, we should not only consider the conditions of ordinary cutting, but also consider the characteristics of the grinding process itself: we all know that the grinding process is actually a Multi Tool simultaneous cutting process. The feed amount of grinding is small and the cutting force is usually small, but the grinding speed is high (30-80m / s). Therefore, the temperature in the grinding area is usually high, up to 800-1000 ℃, It is easy to cause local burns on the surface of the workpiece, and the thermal stress of grinding will cause deformation of the workpiece and even crack on the surface of the workpiece.
At the same time, a large amount of metal grinding debris and grinding wheel dust will be produced in the grinding process, which will affect the surface roughness of the workpiece; Therefore, when selecting the water-soluble metal cutting fluid for grinding, we need the cutting fluid to have good cooling, lubrication and washing and scouring properties. According to the different materials of workpieces, when selecting water-soluble metal cutting fluid, different cutting fluid products should be selected according to the different characteristics of different materials. For example, when cutting high hardness stainless steel, the extreme pressure water-soluble metal cutting fluid with good extreme pressure performance should be selected according to its characteristics of high hardness, high strength and difficult cutting, so as to meet the extreme pressure lubrication performance requirements of the cutting fluid in the cutting process; For materials such as aluminum alloy and copper alloy, due to the characteristics of high toughness and high activity of the material itself, when selecting water-soluble metal cutting fluid, the lubricity and cleaning property of the cutting fluid are required, and the workpiece cannot be corroded.
