Carburization workpiece material is generally low carbon steel or low alloy steel (carbon content of less than 0.25%). After carburization, the chemical composition of steel surface can be close to high carbon steel. After the carburizing after quenching, the wear resistance and fatigue strength, high surface hardness, and keep the core of the strength and toughness of low carbon steel after quenching, so that the workpiece can withstand the impact load. Carburizing technology is widely used in mechanical parts of aircraft, automobile and tractor, such as gear, shaft, cam shaft etc..
In Chinese carburizing process can be traced back to 2000 years ago. The first is by solid carburizing medium carburizing. Liquid and gas carburizing was in twentieth Century and has been widely used. America began using gas carburizing rotary furnace in the 20's.. In 30's, in the industrial application to continuous gas carburizing furnace. 60 in the high temperature (960 ～ 1100 ℃) gas carburizing development. To the 70's, the vacuum carburizing and ion carburizing.
Principle
Carburizing and other chemical heat treatment, also contains 3 basic process.
The decomposition
Decomposition of carbon atoms activated carburizing medium.
The adsorption
Carbon atoms activated by steel surface after absorption solution to the surface of the carbon austenite austenite, the increase in the.
The diffusion