Vacuum Furnace Selection

I. Vacuum heat treatment furnace can be divided into vacuum quenching furnace, vacuum tempering furnace, vacuum annealing furnace and so on.

1. Vacuum quenching furnace; Vacuum quenching furnace can be divided into vacuum oil quenching furnace and vacuum gas quenching furnace.

1.1 Vacuum oil quenching furnace is suitable for vacuum heat treatment of die steel, spring steel, stainless steel, bearing steel, high-temperature alloy steel, etc. Its main features are wide range of applicable materials, strong hardenability, low cost and reusable quenching oil. There are shortcomings. The deformation is relatively large and the workpiece needs to be cleaned later. The vacuum oil quenching furnace can be divided into two-chamber furnace and three-chamber furnace in structure.

1.2 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 disadvantage is that the quenching gas can not be recovered and the cost is high. The vacuum high-pressure gas quenching furnace can be divided into horizontal type and vertical type in structure. 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 needs of users, the furnace type with parts suitable for pressure can be selected.

2. Vacuum tempering furnace: Vacuum tempering furnace can be divided into single chamber, double chamber and vertical type. Generally, nickel-chromium tape is used for heating up to 800 C. Vacuum tempering furnaces are generally suitable for applications requiring bright, non-oxidizing surfaces on parts after tempering.

3. 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 parts materials, (800 ~1350 C at medium and 800 C at low temperature).

II. Selection of Heating Chamber for Vacuum Furnace

1. Graphite reflective screen: Hard felt and soft felt are commonly used in vacuum furnace, which are suitable for quenching, tempering and annealing of general steel. High temperature brazing, powder metallurgy, sintering, etc.

2. Metal heat shield; Stainless steel and molybdenum are commonly used in vacuum furnaces. Molybdenum reflective screen is suitable for quenching, annealing and high temperature of materials requiring high environment in furnace (e.g. superalloy, titanium alloy, magnetic material, etc.).

Temperature brazing, sintering, etc. Stainless steel rice shooting screen is suitable for tempering, low temperature annealing, aging, vacuum aluminium brazing and other low temperature furnaces.

III. Selection of Vacuum Degree

1. Medium vacuum (general limit 0.4pa) can be used for quenching heat treatment. Two-stage pumps (front pump and Roots pump) such as bearing steel, die steel, structural steel, etc. are used for vacuum heat treatment.

2. For some products requiring high vacuum, such as vacuum heat treatment or high-temperature brazing (superalloy, titanium alloy, magnetic material, etc.). Three-stage pumps (front pump, Roots pump, diffusion pump, etc.) can be selected. The vacuum limit is generally 10-4Pa.

IV. Selection of Control System

1. Standard configuration; With the import temperature controller and programmable controller as the core, temperature programmable, manual and automatic control are realized.

2. Computer control system; With the industrial computer and programmable controller as the core process programming, store and make reports. It can be operated independently by computer, automatic, manual, process programming, etc.

3. Computer group control system; The high-tech control system integrates monitoring, data collection, operation and report management of several vacuum furnaces with industrial computer as the core.