Process analysis of heat treatment of key milling cutter using high-frequency induction heating equipment

Key milling cutters are mainly used to process the grooves and tooth shapes of various keys. This type of milling cutter requires high hardness, wear resistance and toughness. Since key processing is mostly dry cutting and high-speed cutting, there are also certain requirements for the thermal hardness of the tool. For this reason, key milling cutters often use high-frequency induction annealing equipment for heat treatment. Below, we will take a look at the high-frequency heat treatment process of key milling cutters.

1) Preheat. Use high-frequency induction heating equipment for preheating heat treatment at 850-870°C. The preheating time is twice the heating time.

2) Heating. Different steel grades have different heating temperatures. The heating temperatures of W18Cr4V, M2, 9341, and W6M05Cr4V2Al (501 steel) are 1260-1280°C, 1220-1230°C, 1225-1235°C, and 1195-1210°C respectively.

3) Cool down. Milling cutters with thickness <2.Omm adopt graded isothermal quenching, that is, after graded at 580-620℃, they are immediately transferred to the nitrate salt isothermal temperature of 260-280℃ for 1.5h, and air-cooled after coming out of the furnace. For thickness >2.Omm, the conventional quenching process of air cooling at 580-620℃ after classification is adopted. The classification time is the same as the high temperature heating time.

4) Tempering. Graded austempering milling cutters with a thickness of ≤2.0mm should be tempered using high-frequency induction annealing equipment after cleaning. The first tempering heat treatment is 350~380℃x4h, and the last three temperings are at 540-560 as usual. ℃x lh process. For graded quenching, use 540-560℃xlhx3 times of conventional tempering.

5) Inspection. Mainly check hardness, metallography, bending and surface quality according to technical requirements.

Since we just said that key milling cutters are used to process the grooves and tooth shapes of various keys, the relationship between key milling cutters and keys is very close. The quality of the key milling cutter's heat treatment directly affects the quality of the key, so it is necessary to produce high-quality key milling cutters. Today, we briefly talked about the high-frequency heat treatment process of key milling cutters. As for other specific processes, you need to explore it yourself.