Chemical surface heat treatment
The typical process of surface alloying technology is chemical surface heat treatment. It is a heat treatment process in which the workpiece is placed in a specific medium for heating and insulation.
So that the active atoms in the medium can penetrate into the surface of the workpiece to change the chemical composition and organization of the surface of the workpiece, and then change its performance.
Compared with surface quenching, chemical surface heat treatment not only changes the surface structure of steel, but also changes its chemical composition.
According to different elements infiltrated, chemical heat treatment can be divided into carburizing, nitriding, multi-element co-infiltration, and other elements infiltration.
The chemical heat treatment process includes three basic processes: decomposition, absorption and diffusion.
The two main methods of chemical surface heat treatment are carburizing and nitriding. Compared, carburization, Nitriding.
Improve the surface hardness, wear resistance and fatigue strength of the workpiece, while maintaining good toughness in the heart. Improve the surface hardness, wear resistance and fatigue strength of the workpiece, and improve the corrosion resistance.
Low carbon steel containing 0.1-0.25% C. The higher the carbon, the lower the toughness of the heart. It is a medium carbon steel containing Cr, Mo, Al, Ti, and V. Common method
Gas carburizing method, solid carburizing method, vacuum carburizing method
Gas nitriding method, ion nitriding method
Generally 0.5～2mm and no more than 0.6～0.7mm
It is widely used in mechanical parts such as gears, shafts, camshafts, etc. of airplanes, automobiles and tractors. Used for parts with high wear resistance and precision requirements and heat-resistant, wear-resistant and corrosion-resistant parts.
Such as the small shaft of the instrument, the light-loaded gear and the important crankshaft, etc.