Vacuum Quenching Furnace: A Comprehensive Overview

Vacuum quenching furnace is a kind of equipment that utilizes a vacuum environment to heat and quench metal materials. It is named for its heat treatment in an oxygen-free environment, which helps to prevent oxidation and decarburization of metal materials, resulting in better surface quality and mechanical properties of the treated materials.

As a professional electric furnace manufacturer, Brother Furnace has also dabbled in vacuum quenching furnaces. Taking the quenching furnace produced by Brother Furnace as an example, we will introduce the relevant knowledge of vacuum quenching furnace for you in detail.

What does “VACUUM” and “QUENCHING” Mean?

To understand what a vacuum quenching furnace is, it is important to first understand the concepts of vacuum and quenching separately.

"VACUUM"

When metals are heated in oxidizing gases such as oxygen, water vapor, and carbon dioxide, oxides are produced due to the affinity of the metal.

However, when heated in vacuum, because the partial pressure of oxygen is lower than the decomposition pressure of oxides, the oxidizing effect is suppressed, and the purpose of no oxidation is achieved, so that the surface of the metal maintains its original bright surface.

At the same time, for the surface itself contains oxide impurities of the metal, these metals in the vacuum heating will occur after the decomposition reaction, which is conducive to the purification of metal impurities.

Because this environment effectively avoids oxidation and discoloration of metals during high-temperature treatment, Brother Furnace has applied the technology of heating in vacuum in many of its equipments.

"QUENCHING"

Quenching is a heat treatment process in which metal materials are heated to a specific temperature and then rapidly cooled to change their physical and mechanical properties.

This process not only helps to improve the hardness and strength of materials such as metal but also helps to make the surface of the metal bright and clean.

Classification of Quenching

Quenching can be categorized into oil quenching and gas quenching. Oil quenching and gas quenching are two different cooling media used in the quenching process, applicable to different materials and process requirements.

Oil Quenching

1. Cooling medium: special quenching oil is used.

2. Cooling speed: the cooling speed of oil is relatively slow, which can avoid excessive internal stress and deformation of the material due to rapid cooling.

3. Applicable materials: applicable to alloy steel and high carbon steel, etc., as well as materials that do not require high cooling speed and need to avoid quenching cracking.

4. Advantages: It can effectively reduce quenching cracks and deformation; suitable for workpieces with large sizes or complex shapes.

Air Quenching

1. Cooling medium: use air or inert gas (e.g. nitrogen, argon).

2. Cooling speed: relatively slow, usually used for materials that do not require high cooling speed.

3. Applicable materials: for some alloy tool steel and complex shape or thin-walled workpieces.

4. Advantages: no pollution, friendly to the environment; with high control precision, so the workpiece deformation is small.

To summarize, oil quenching is suitable for workpieces that require a faster but not as fast cooling rate as water and are prone to deformation and cracking, while gas quenching is suitable for occasions that require a slower cooling rate and higher deformation control.

According to the nature of the material and process requirements to choosing the appropriate quenching method is to ensure the quality of the workpiece key.

Application Fields

As the following examples show, vacuum quenching furnaces from Brother Furnace are now used in a wide range of applications.

Aerospace: For treating high-strength alloy materials and complex shaped parts to improve their wear resistance.

Automotive: For quenching engine parts, gears, bearings, etc. to improve their service life and reliability.

Material Processing: Used for quenching and tempering of steel to enhance hardness and wear resistance.

Electronics: Used to treat microelectronic components and precision parts to reduce surface defects and internal stress.

How to Operate a Vacuum Quenching Furnace

● Preparation: Clean the workpieces to be treated and make sure the surface is free of oil and impurities to prevent affecting the quenching results of the workpieces.

● Loading: According to the shape and size of the workpieces choose the appropriate way of loading the furnace, to ensure that the workpieces is uniformly heated.

● Vacuum extraction: After the workpieces are loaded into the furnace, the first thing to do is to exhaust the gas. Start the vacuum pump to evacuate the gas inside the furnace, and begin to heat when it reaches the predetermined vacuum degree.

● Heating: Set the heating temperature and time according to the process requirements, and start the heating system. Before formal heating, it is usually preheated to make the temperature of the workpiece and the furnace temperature the same and make the workpieces heated evenly.

● Holding: After the target temperature is reached, it is held for some time to ensure that the internal temperature of the workpiece is uniform.

● Quenching: After the holding time is over, gas is passed into the furnace and the cooling system is quickly turned on. Use a suitable cooling medium to cool the workpieces quickly.

● Tempering: After quenching, tempering treatment can be carried out as required to reduce the internal stress of the workpieces and improve their toughness.

● Unloading: After cooling is completed, stop the vacuum pump. Open the furnace door and remove the workpieces.

Frequently Asked Questions

1. Why quench in a vacuum environment?

A vacuum environment prevents oxidization and decarburization of metals at high temperatures and improves the surface quality and mechanical properties of workpieces. In addition, vacuum quenching reduces distortion and internal stress, making it suitable for handling precision parts and high-performance materials.

2. What are the advantages of vacuum quenching furnace compared with the traditional quenching furnace?

Vacuum quenching furnace has the advantages of even heating, no oxidation, small deformation, stable performance, etc. It is suitable for processing high requirements and complex shape workpieces. In addition, it is environmentally friendly and reduces the emission of harmful gases.

3. How to choose a suitable vacuum quenching furnace?

When choosing a vacuum quenching furnace, you should select the appropriate furnace type and configuration according to the material, shape, size, and output requirements of the workpieces.

If you have any questions about ordering a vacuum quenching furnace, please feel free to contact us, Brother Furnace will give you targeted advice according to your situation.

4. After vacuum quenching, why do some workpieces need to temper?

Tempering is to reduce the internal stresses generated during the quenching process and to increase the toughness and stability of the workpieces. By proper tempering treatment, cracking, and deformation of the workpieces during use can be avoided.

Summary

We offers both vacuum gas quenching furnace and vacuum oil quenching furnace for customers to select from. Nowadays, the vacuum quenching furnace from Brother Furnace has become the choice of more and more countries and regions because of its stable and reliable performance.

After more than ten years of continuous development and innovation, Brother Furnace always believes that the trust of customers is our greatest support, and the praise of customers is the most lasting motivation for us.

Brother Furnace promises you that the best products and services will be provided to you with the greatest enthusiasm.