40Cr steel and carbide brazing

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Carbide gear hobbing cutter is widely used in production, which can be used to process various kinds of gear, and can be used to replace tooth grinding process when hard gear is processed.This hobbing cutter is made of YT50 carbide and 40Cr medium carbon steel by vacuum brazing process.
1. Gear hobbing cutter is made of 40Cr steel and YT50 carbide.

2. filling material

A. The sheet pure brazing filler metal BCu(cu99.95%) with a thickness of 0.2mm is selected for the brazing alloy. The melting temperature is 1083℃ and the brazing temperature is 1100 ~ 1150℃.

B. Flux brand YJ1 is selected, the main component is borax, and the brazing temperature is 800 ~ 1150℃.QJ201, hard flux can also be used, the components of pouring: boric acid 80%, borax 14.5%, calcium fluoride 5.5%;Brazing temperature is 850 ~ 1150℃.

3.Brazing operation key point

A. Cut the solder metal according to the tooth shape and place it between the cutter body and the blade.Fix the blade on the knife body with a clamp. Apply flux to the contact part between the clamp and the welding piece, and then put it into the vacuum furnace.

B. Vacuum the furnace to 5× 10-2pa in cold state, and then heat the furnace to 1000℃ at the speed of 450℃/h, and fill the furnace with high-purity argon gas to ensure the pressure in the furnace is 2 ~ 3Pa, and stabilize for 30 ~ 40min, so that the temperature inside and outside the knife body is uniform.

C. Heat the furnace temperature to 1120℃ at the speed of 250℃/h and keep it warm for 15min. Then cool the furnace temperature to below 900℃ with the pressure inside the furnace.

D. When the furnace temperature is cooled to below 400℃, increase the argon filling amount to increase the pressure in the furnace to 8×104Pa, and then start a fan to stir argon, and the furnace temperature is cooled to below 65℃.

E. After the hobbing cutter is out of the oven, it is forbidden to collide with each other, and it is naturally cooled in the air. At this time, the ambient temperature of the workshop should not be lower than zero.

F. After the knife body and blade are completely cooled and contracted, slowly remove the fixture, so that the fixture and hobbing cutter are not damaged, and clean up brazed hobbing cutter.