The heat treatment process of the file is as follows: heating-cooling-heat straightening-cooling to room temperature-cleaning-tempering-cleaning-inspection. During the preparation and operation of the heat treatment process, preventing tooth quenching and decarburization and having skilled straightening techniques are the keys to file heat treatment. Therefore, high-frequency induction heating is generally carried out, or treatment in a controlled atmosphere furnace, if there is no condition, It can be carried out in a salt bath furnace containing yellow blood salt. The general composition of yellow blood salt is: sodium chloride 50% + yellow blood salt 35% + sodium carbonate 15%. According to the information, the composition of yellow blood salt can fluctuate in the range of 10% to 40% in the actual heating process.
The heat treatment process is as follows:
1. The heating temperature is 750～790℃, and the holding time should be selected correctly according to the different heat treatment equipment.
1. The heating temperature is 750～790℃, and the holding time should be selected correctly according to the different heat treatment equipment.
2. The cooling medium is 10% salt water or flowing clean water, and the temperature should be lower than 30°C to ensure sufficient cooling performance and high hardness for the file.
3. The low-temperature tempering of the file is usually carried out in a nitrate furnace, the temperature is 160-180℃, and the time is 60-90min.
Matters needing attention in heat treatment process:
1. The file is cooled to the range of 180～200℃ in the cooling medium, and it should be taken out and straightened by hand immediately. The file is straightened in a short period of time and then put into the medium to cool it through, and it is completely hardened.
1. The file is cooled to the range of 180～200℃ in the cooling medium, and it should be taken out and straightened by hand immediately. The file is straightened in a short period of time and then put into the medium to cool it through, and it is completely hardened.
2. There are four ways to reduce the hardness of the handle: one is to heat the handle in a salt bath furnace for a short time and then it is oil-cooled; the other is to temper the handle at about 500℃ and then cool it in oil; the third is to The handle is subjected to high-frequency induction heating; when the final quenching is used, the teeth of the file are filled with water first, and the handle is cooled as a whole when it is dark red.
3. The cooling technique of the file. The arc part of the semicircular file is easy to bend to the inside when it is cooled, and it is pre-deformed; or the arc face downwards and enters the water at 45° with the medium. For flat files, round files, triangle files, and square files, they are placed perpendicular to the liquid surface.
4. The straightening temperature of the file should be controlled correctly, the hardness of the file will be low if the water is discharged early; the water will be difficult to straighten if the water is discharged late, and even cracks and breaks may occur.
To ensure the smooth production of parts in the heat treatment process, it is an important part of the heat treatment process document.
