PSI - Issue 39

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N.A. Makhytov et al. / Procedia Structural Integrity 39 (2022) 266–272 Makhutov N.A./ Structural Integrity Procedia 00 (2019) 000–000

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(a)

(b)

Fig.2. (a) Device for fixing exact nets on surfaces sample; (b) the cylindrical tubular sample on test machine UME-1000 kN with optical system. Illustration of the developing crack is brought on Fig. 2b on surfaces sample. Typical path of the development of the crack and zone of the fracture are shown (Fig. 3) in its top.

(a)

(b)

/ 4 π β = (x60); (b) zone of the fracture in top

Fig. 3. (a) Path of the developing crack on surfaces sample with source corner of the slopping

of the crack (x100).

Typical devil observed micro relief to surfaces of the fracture is a change the direction of the development of the crack when turning from grain to grain (10 О – 25 О ) and presence carbon cut-in on border grains (Fig.4a). On (Fig. 4b) and (Fig. 4 c) are shown after fracture of the surfaces of the crack of the normal take-off / 2 π β = and with source corner of the slopping / 3 π β = . Appearance threshold fracture on surfaces developed crack with source corner of the slopping / 3 π β = (Fig.4c) illustrates essential influence IIe K and IIIe K