Processing is a phenomenon that increases hardness by adding stress (strain that occurs inside) to metal, and occurs when metal is plastic deformation. In cutting processing, processing heat and plastic deformation during work cutting causes processing and curing. It is a processing and curing generated by most metals, but it is inevitable, especially in cutting processing, to achieve the target shape by a series of plastic deformation. This article explains the causes of processing and curing in cutting and countermeasures.
In order to grasp the mechanism of processing and curing, it is important to know how the arrangement of atoms that make up metal changes when plastic deformation occurs. The positional relationship of each atoms changes by applying force in metal atoms, which are neatly arranged in a lattice. Up to a certain amount of deformation will return to the original positional relationship by removing the applied force, but if the amount of deformation exceeds a certain amount of deformation, the atoms will be disturbed (transfer) and will not return to the original shape.
The phenomenon that increases metal hardness due to this transition is "processed hardening". The indicator of each material quantitatively represents "how much processing is easy to harden" is called N value. The N value indicates that the larger the value, the easier it is to process, and the N value of the typical materials is as follows. Material N value soft steel 0.21 copper (O material) 0.50 copper (1/2 material) 0.05 Aluminum alloy (A1100-0) 0.26 titanium 0.14sus3040.42sus4300.23
The following effects of processing and curing on cutting tools and products are listed as follows. id = "" that affects tool lifeProcessing that affects the dimensions of the product may occur in almost all processing processes, so it is necessary to consider countermeasures for each process.
One of the factors that affects the life of the cutting tool is the relationship between the cutting tool and the hardness of the work. It is important to note that if the hardness of the cut tool is high, the wear of the tool will be promoted and the life will be shortened. In the cutting surface, the cutting surface of the work causes processing and curing, increases the hardness and affects the life of the tool.
Processed and cured at the time of cutting affects the dimensional accuracy of the product to be processed. The processing and curing may cause a tool abnormality, such as a chipping tip of the tool used for later cutting, because the work becomes harder than the original expected. When a chipping occurs, the cutting surface is deteriorated by increasing the cutting resistance, which deteriorates the dimensions of the product. In the case of precision processing, which requires high accuracy, it is necessary to pay attention to the occurrence of chipping by processing and curing and the deterioration of dimension accuracy.
The ease of occurrence of processing and curing depends on the material and processing conditions for processing. For example, when a material with a large N -value such as SUS, heat -resistant, high -carbon steel, and alloy steel is processed, processing is more likely to occur compared to materials with low N values. In addition, even in scenes where the temperature of the processing point is too high, or even in scenes where the cutting resistance is high and the temperature is likely to rise, processing and curing are likely to occur. It is possible to consider effective measures by understanding the processing status that tends to be processed and cured.
Countermeasures for processing and curing can be classified into measures by selecting tools and cutting conditions.
As a countermeasure by selecting tools, it is important to consider cutting -edge shapes and cutting tools and hoodles.
If the cutting resistance is high, the processing and curing will be more likely to occur, so selecting a sharp tool will reduce the resistance. Taking into account the shape of the cut -blade, the angle of the cut blade on the work, the hardness of the cutting tools and the work, it can be difficult to generate processing and curing.
Tools and holders are also important to prevent the processing temperature rising to promote processing and curing. In the processing that is difficult to reach external coolants, such as inner diameter processing and deep holes, it is possible to prevent temperature rising by selecting tools and holders that prevent the coolant from rising temperature from the edge of the blade. By preventing temperature rise during processing, it can suppress processing and curing.
As a countermeasure by cutting conditions, it is important to have a processing path, cooling of cutting, and temperature control of cutting points.
Rubbing is generated between the cutting tool and the work, causing a load on the rubbed part and processing processing. For example, by selecting a processing path that realizes the target shape, while avoiding the processing of rubbing as much as possible, it is possible to make it less likely to be affected by processing and curing.
Cooling at the pointing point is effective because the temperature of the cutting point is highly generated and the processing is likely to occur. By using a coolant, you can expect cleaning, improving lubricity, and cooling the cutting point. It is important to supply coolants according to the application from various types, such as cooling and lubrication, with appropriate methods.
It is also effective to keep the temperature constant so as not to increase the temperature of the cutting point too much. By adjusting the processing conditions such as cutting speed and tool sending speed, it is possible to adjust the heat load generated between the tools and the work, and keep the temperature of the cutting point constant.
In this article, we explained the causes of processing and curing in cutting and countermeasures. It is a processing and curing that cannot be passed by cutting processing, but the key to the highly accurate processing is to grasp the materials that are generated and their mechanisms, and use different cutting tools and cutting conditions according to the situation.
