PSI - Issue 20

Valeriy Lepov et al. / Procedia Structural Integrity 20 (2019) 57–62 Valeriy Lepov et al. / Structural Integrity Procedia 00 (2019) 000–000

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characterized by existence of brilliant flat sites on the fracture surface. At a ductile break the surface of destruction contains small fines or cavities which are formed at plastic deformation of grains in the process of fracture. In this regard the microstructural analysis of breaks of the studied material was carried out. As shown on high resolution images, the most part of break surfaces of the samples from the notch as a stress concentrator to a cut or rupture represents the fragile fracture. Nevertheless there is a numerous branching cavities on breaks characterized the fatigue process (see Fig. 3a).

KCV, J/cm2

T, °C

Fig.1. Experimental impact toughness dependence on temperature.

Fig. 2. The breaks of samples tested at –60 °C.