The Carburization Process of Carburizing Agents in Casting and Steelmaking
Due to their low carbon content, low-carbon steel is neither too tough nor too brittle, and their tensile strength and hardness are both very low. Due to its low hardness, it exhibits severe wear during sliding and rolling contact with harder materials. Increasing the carbon content of steel can improve its strength and hardness. It has also become less resilient (with lower fatigue strength and greater brittleness), and its weldability and workability have been affected.
What is a carburetor?
Carburizer is the process of hardening the exterior of Ferrous workpiece (component) by promoting the diffusion of carbon atoms to the surface to a certain depth. It is one of the common methods for hardening the outer layer of metal parts.
Before starting disposal, the surface to be disposed of must be thoroughly cleaned to remove pollutants. During the carbonization process, the metal workpiece to be hardened on the surface is heated in an environment rich in carbon gas, liquid, or solid. In the heating process, the carbon source (the catalyst in the carbonization process) is synthesized and releases carbon atoms, which diffuse to the surface of Ferrous. Low carbon steel and some alloy steel commonly use carburization process to stop heat treatment., The speed of carbon diffusion depends on temperature and the carbon potential of the heat treated metal, while the depth of the carburized layer depends on the carbon diffusion temperature, the carbon potential of the metal surface, and the duration of carburization.
Metals are composed of atoms and molecules tightly separated in lattice structures. (Understanding the crystal structure of metals) Free carbon atoms in carbon containing materials (solid, liquid, plasma, or gas) diffuse into the crystal structure, thereby increasing the carbon content and achieving a certain depth of hardness on the surface of the workpiece.
The carburization process is used to improve the following characteristics of alloy steel and low-carbon steel workpieces: mechanical strength, toughness, wear resistance, corrosion resistance, fatigue strength, ductility, external hardness, and elimination of internal stress.
During the carburization process, the temperature of the workpiece remains between 850 ° C and 950 ° C (1560 ° F to 1740 ° F), which is higher than the critical temperature of the steel and the duration depends on the expected depth of the hardened shell. After the carburization process is completed, the workpiece is quenched, causing carbon atoms to adhere to the interior of the metal structure.
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