During the induction heat treatment process, some process parameters such as heating, cooling, self-tempering, affecting the quality of the quenching parts, so it is necessary to comply with the relevant process regulations. Dongguan Guangyuan variable frequency sensing heating equipment found some provisions on the development and execution of the induction heat treatment process.
1.Heating
(1) For the purpose of heating: 1 When heating is completed, the temperature of the surface layer of the part should be equal to or slightly higher than the quenching temperature; 2 obtaining a suitable heating layer depth
(2) The depth of heating temperature and the heating layer depends on the following factors: 1 The average effective power of the part is transmitted within the heating time; 2 heating time; 3 current frequency.
2. Cooling parts should be cooled immediately after heating or cooled after a certain pre-cooling time to complete quenching.
(1) The advantages and disadvantages of the quenching results are in the following three aspects: 1 The hardness value is directly measured after cooling; 2 in the size of the internal stress; 3 depth, region and microstructure of the hardened layer.
(2) The quenching results are determined by the following parameters: 1 cooling time; 2 temperature of the quenching cooling medium (water, oil, polymer solution, etc.); 3 pressure (or flow) when quenching the cooling medium is discharged.
3. Self-tempered
(1) The result of the self-return fire is: 1 decrease in quenching hardness; 2 degree of internal stress elimination.
(2) The result of the self-return fire depends on: 1 high temperature of the temper; 2 self-recovery time.
(3) Inspection of self-recovery quality: 1 When the quenching hardness is reduced, the self-tempering part is compared with the non-self-tempered replacement and the parts without self-return (quenching), which can be dense to make the part hardness Reduced value; 2 Check that there is no quenching fire crack; 3 Use the file with the stem of the spray, observe the surface tempering color (oxidation) can substantially determine the self-recovery temperature; 4 use infrared thermometer directly to measure the self-return Fire temperatures are reliable.