On 2018-08-08 14:48:54
Chemical heat treatment workpiece
Hardness test of chemical heat treatment workpiece
There are three kinds of hardness testing standards for heat treatment, Vickers, Rockwell and surface Rockwell. According to different heat treatment methods, the hardness testing methods of surface quenching annealing heat treatment furnace and chemical heat treatment furnace are also different.
The main technical parameters of the chemical heat treatment workpiece are the hardened layer depth and surface hardness. The hardened layer depth shall be tested by Vickers hardness tester. The distance from the workpiece surface to the point where the hardness drops to 50 HRC shall be tested, which is the effective hardened depth.
Chemical heat treatment is to make the surface of the workpiece permeate with atoms of one or several chemical elements, so as to change the chemical composition, structure and performance of the surface of the workpiece. After quenching and low temperature tempering, the surface of workpiece has high hardness, wear resistance and contact fatigue strength, while the core of workpiece has high strength and toughness.
The surface hardness test of the chemical heat treatment workpiece is similar to that of the surface quenching heat treatment workpiece, which can be tested by Vickers hardness tester, surface Rockwell hardness tester or Rockwell hardness tester, but the thickness of the nitriding thickness is relatively thin, generally not more than 0.7mm, at this time, Rockwell hardness tester can no longer be used.