Analysis of the origin and development of fatigue failure in pearlitic steels

A deformation-force equation of fatigue failure of polycrystalline body-centered cubic metals is obtained. A comparison is made of calculations using the proposed equation with experimental data on life in the stage of crack origin in nonsteady (two-block) loading. It is shown that the decrease in the share of quasicleavage with an increase in the range of stress intensity factor K resulting from the model considered agrees with teh results of fractographic investigations. Theoretical and experimental invetigations are made of the influence of the substructure formed during deformation on the conditions of development of damages in cyclic loading.Translated from Problemy Prochnosti, No. 4, pp. 12–21, April, 1990.     

Preliminary compression of a material as a factor in changing the brittle fracture mechanism for BCC metals

We have investigated the effect of preliminary plastic compression on the characteristics of brittle fracture in bcc metals using 15Kh2MFA pearlitic steel as an example. We have experimentally established that preliminary plastic compression of the material leads to a change in the mechanism of brittle fracture from transcrystallite to intercrystallite. We have shown that the critical stress for brittle fracture is significantly lower for the intercrystallite mechanism than for the transcrystallite mechanism. We suggest mechanisms for embrittlement of material as a result of its preliminary plastic compression. We present schemes for the transition from intercrystallite fracture to transcrystallite, depending on the thermal and mechanical loading conditions for the precompressed material.Translated from Problemy Prochnosti, No. 4, pp. 5–18, April, 1996.     

Analysis of certain problems of the brittle fracture of bcc metals

Strength of Materials - A physicomechanical analysis is made of the conditions under which brittle fracture occurs in bcc metals. A criterion of brittle fracture is formulated on the basis of a...