What is the working principle of a pit carburizing furnace?

2024-09-12 09:11:11

A Pit Carburizing Furnace is a device used for heat treatment of metal surfaces, mainly used for carburizing processes to improve the hardness and wear resistance of metal surfaces. Its working principle involves several key steps, as follows:
1. Carburizing principle
Carburizing is a process that changes the physical properties of a metal by diffusing carbon elements into its surface. By increasing the surface carbon content, the hardness and wear resistance of the metal can be significantly improved. This process is often used for surface treatment of alloy materials such as steel.
2. Furnace structure
Pit Carburizing Furnaces are usually designed as vertical well-shaped structures, and the internal space can accommodate multiple workpieces. The furnace body is equipped with heating elements to ensure uniform temperature distribution in the furnace, and has good thermal insulation to reduce heat loss.
3. Heating process
During the carburizing process, the temperature in the furnace is first raised to a set value, usually between 850°C and 950°C. The heating elements in the furnace body (such as electric heating tubes or gas heaters) conduct heat to the workpiece to ensure that the metal reaches the required temperature and promotes the diffusion of carbon.
4. Atmosphere Control
The atmosphere in a pit carburizing furnace is usually composed of carbon-containing gases (such as methane, ethylene or ammonia). By adjusting the flow rate and concentration of the gas, the carbon source in the furnace can be controlled. When the gas decomposes at high temperatures, carbon atoms are released, which diffuse to the metal surface.
5. Diffusion of Carbon
At high temperatures, carbon atoms diffuse into the surface of the metal to form a carbon-rich area. The depth of this process and the concentration of carbon can be precisely controlled by adjusting the heating time, temperature and composition of the atmosphere.
6. Cooling
After carburizing, the workpiece is removed from the furnace and is usually cooled rapidly (such as water quenching or oil quenching) to lock the distribution of carbon in the metal surface and improve its hardness and strength. The choice of cooling rate affects the microstructure of the final material.
7. Post-treatment
After carburizing and cooling, the workpiece usually needs to be subjected to subsequent treatment, such as tempering, to eliminate internal stresses and improve toughness. This process can improve the durability of the material and prevent brittle failure.
8. Application
Pit carburizing furnaces are widely used in surface treatment of mechanical parts, such as gears, shafts, dies, etc., to meet the requirements of material properties in different industrial fields.
In summary, pit carburizing furnaces effectively improve the hardness and wear resistance of metal surfaces by precisely controlling temperature, atmosphere and treatment time, providing important material treatment technology for modern industry.