Vacuum annealing high quality spring steel, tool steel, precision steel pipe wire, stainless steel products and titanium alloy materials, bright annealing can be used for vacuum treatment. The lower the annealing temperature, the higher the vacuum is required. In order to prevent the evaporation of chromium and accelerate heat conduction, generally use carrier gas heating (heat preservation) method, and pay attention to the stainless steel and titanium alloy should not use nitrogen but argon.
Precision steel tube process
Vacuum quenching furnace can be divided into oil quenching and gas quenching according to the cooling method, and can be divided into single chamber type and double chamber type according to the number of working positions. Vacuum oil quenching furnace is a double chamber, the rear chamber electrical heating elements, the front chamber below the oil groove. After the workpiece is heated and kept warm, it will be moved to the front chamber. After the middle door is closed, the front chamber will be filled with inert gas to about 2. 66% 26 times; LO ~ 1. 01% 26 times; 10 Pa(200 ~ 760mm mercury column), oil. The surface deterioration of workpiece is easily caused by oil quenching. Due to the high surface activity, significant thin layer carburization can occur under the action of short high temperature oil film. In addition, the adhesion of carbon black and oil on the surface is unfavorable to the simplified heat treatment process.
The development of vacuum quenching technology mainly lies in the development of gas quenching furnace with excellent performance and single station. The said double-chamber furnace can also be used for gas quenching (air cooling in the front chamber), but the double-station operation makes it difficult to produce large quantities of furnace loading, and it is easy to cause workpiece deformation or change workpiece orientation to increase quenching deformation during high temperature movement. Single station gas quenching furnace is in the heating room after the completion of heat preservation air cooling.