Low-frequency internal friction investigating of the carbide precipitation in solid solution during tempering in high alloyed martensitic steel

In this paper, the mechanical properties and the internal friction (IF) of high alloyed martensitic carbon steel were investigated. The relationships between the internal friction and mechanical properties of the steel containing 0.98 wt.% carbon were researched using dilatometer, X-ray diffraction, Rockwell hardness and impact toughness. The samples were quenched and tempered in order to vary the concentration of carbon in solid solution in the martensite. The internal friction was measured in an inversed torsion pendulum with high vacuum using free decay method. The behavior of dislocations and their interactions with point defects were analyzed through the changes of the internal friction spectrum.