Vacuum Gas Quenching Furnace for High Speed Steel
The main structural components of vacuum gas quenching furnace in vacuum furnace, the structure composition of shell, door and gear ring which affect the safety of equipment. Because of the particularity of vacuum gas quenching furnace in alternating positive and negative pressures, in order to ensure the safety of equipment and realize the economy of equipment, theoretical calculation of shell and gear ring is carried out by calculation method and drawing method, and safety analysis of structure is carried out by finite element analysis method. Structural optimization of weak links in the design structure is carried out through mechanical model to meet the requirements of structural safety.
There are two kinds of quenching in vacuum: gas quenching and liquid quenching. Gas quenching is to cool the workpiece by filling high purity neutral gas (such as nitrogen) into the cooling chamber after vacuum heating. Material with low critical cooling rate of martensite, such as high speed steel and high carbon high chromium steel, is suitable for gas quenching. Liquid quenching is to heat the workpiece in the heating chamber, then move it to the cooling chamber and fill it with high purity nitrogen gas and send it to the quenching tank immediately for rapid cooling. If high surface quality is required, tempering and precipitation hardening of workpiece after vacuum quenching and solution heat treatment should still be carried out in vacuum furnace.
Vacuum quenching furnace: Vacuum quenching furnace can be divided into vacuum oil quenching furnace and vacuum gas quenching furnace.
Vacuum tempering furnace: Vacuum tempering furnace can be divided into single chamber, double chamber and vertical type. Usually, nickel-chromium strip is used to heat the highest temperature of 800 C. Vacuum tempering furnace is generally applicable to require that the surface of parts after tempering is bright and no oxidizing color.
Vacuum annealing furnace: Vacuum annealing furnace can be divided into single chamber, double chamber and vertical type. Vacuum annealing furnace can choose medium and high temperature and low temperature according to the material of parts, (medium and high temperature 800 C~1350 C, low temperature 800 C).
Vacuum oil quenching furnace is suitable for vacuum heat treatment of die steel, spring steel, stainless steel, bearing steel, superalloy steel, etc. Its main characteristics are wide range of suitable materials, strong hardenability, low cost and reusable quenching oil. The shortcomings are: the deformation is relatively large, and the workpiece needs to be cleaned in the follow-up. The vacuum oil quenching furnace can be divided into two-chamber furnace and three-chamber furnace.
Vacuum high pressure gas quenching furnace is suitable for vacuum heat treatment of high speed steel, stainless steel, die steel and other materials with good hardenability. It is characterized by small deformation of parts and no cleaning after heat treatment. The shortcomings are that quenching gas can not be recovered and the cost is high. Vacuum high pressure gas quenching furnace can be divided into horizontal type and vertical type. Horizontal type can be divided into single room, double room and three rooms. Vertical type is suitable for heat treatment of ring-shaped, cylindrical and long rod-shaped parts. The quenching pressure of vacuum high pressure gas quenching furnace is generally 2B a r~10b a r. According to the user's needs, we can choose the furnace type which is suitable for pressure.