Simulation of the distortion of 20MnCr5 parts after asymmetrical carburization

The carburization of steel parts changes the chemical composition in the surface. According to the change of chemical composition a change in density occurs. If the change in density is distributed in an asymmetrical way, distortion can not be avoided. In order to find out the effects of specifying factors on distortion, several finite element simulations of asymmetrically carburized 20MnCr5 discs were carried out. All simulated activities during the carburizing process occur at austenitization temperature. First, an analysis with several geometries - with changed radii and changed thicknesses - shows, that the influence of the partial carburization on distortion decreases exponentially with increasing thickness of the disc. Second, an analysis with four different carbon profiles shows, that a change in carbon profile leads to different distortion behaviour. In order to check the quality of the calculated results, the distortion of a partially carburized and afterwards oil-quenched disc was measured by coordinate measurements. This result was compared with the simulated distortion and shows a good agreement.