Bestimmung der Streckgrenze und der Hall‐Petch‐Konstanten des Vergütungsstahles 42CrMo4 unterschiedlichen Gefüges mittels Eindruckprüfungen

Determination of yield stress and Hall‐Petch coefficients of the tempering steel 42CrMo4 with different microstructure by means of indentation testing Yield stress of steels can be determined by tensile tests or by indentation testing. Indentation tests offer the advantage of measuring the yield stress of certain parts that otherwise could not be used to withdraw tensile samples. Furthermore, measurements in parts with a varying yield stress e.g. surface hardened steels can be carried out. This work investigates several methods of indentation tests to measure the yield stress of the tempering steel 42CrMo4. The yield stress of different microstructures is compared to results of tensile tests. Using the indentation test according to GOST 22762‐77 the Hall‐Petch coefficients of microstructures consisting of perlite and ferrite are determined. Thus the influence of grain size and distance of perlite lamellas on the yield stress can be taken into account.