Modification of Surface Structure by Diffusion Processes

Abstract

In the paper an effect of a diffusion technology such as gaseous ferritic nitrocarburizing on the surface properties of selected alloyed case-hardening steel was tested. The steel 18CrNiMo7-6, primarily predetermined for carburizing and frequently utilized in manufacturing of highly strained components, where high core tensile strength as well as hard surface is demanded, was exposed to gaseous ferritic nitrocarburizing. Such treated surface was subjected to experimental methods. The microstructure observation and the determination of the white layer thickness was performed on the Opto-digital microscope Olympus DSX500i. The nitriding hardness depth of the surface layer from the microhardness profiles obtained by the microhardness tester LM247 AT LECO was deduced. The wear resistance was assessed by utilizing the Scratch test method performed on the tribometer Bruker UMT-3 TriboLab. Results of the measurements present an effect of gaseous ferritic nitrocarburizing on the surface properties of the steel 18CrNiMo7-6 and provide a perception of possibility to substitute the frequently utilized carburizing by the gaseous ferritic nitrocarburizing.