Abstract
Modern gas-carbonitriding processes are enabling smart material properties and an extension of materials’ strength, so that the limit of use of a given alloy and component can be expanded. Recently, a rapid development of the understanding of microstructure development during carbonitriding and in-depth investigation of the microstructure by the means of electron backscatter diffraction (EBSD) was performed. The paper will show examples for the treatment of different case-hardening steels and the development of the microstructure in the final carbonitrided case. It will be shown that a multi-phase microstructure can be varied by process variations from a two-phase martensite and austenite microstructure to a multi-phase microstructure consisting of martensite, austenite, and precipitations. The kind of precipitations emerging and their specific arrangement will be discussed.