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Crack determination . Made by Voronova O.Y. Scientific supervisor – Volchuc V.N. Language supervisor – Kuznecova E.S. Crack . Can be defined as an extreme defect, being a region with completely broken atomic bonds (bank of cracks) and partly broken atomic bonds (crack tip). Fracture.
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Crack determination Made by Voronova O.Y. Scientific supervisor – Volchuc V.N. Language supervisor – Kuznecova E.S.
Crack Can be defined as an extreme defect, being a region with completely broken atomic bonds (bank of cracks) and partly broken atomic bonds (crack tip).
Fracture Brittle fracture Ductile fracture
General Information -Experimental determination of crack -structural features -specimen “compact” model -stress intensity
The influence of structural features • brittle fractures; • larger grains of ferrite; • distribution of cementite (Fe3C); • impurities effect.
The effect of additives -oxygen,nitrogen,phosphorus, sulfur,silicon -vanadium,cobalt ,chromium -manganese,copper,nickel
Standard sample Parameter of fracture toughness-is a property of material characterizes its viscosityor ability to slow down the destruction
Stress intensity (29.6(-185.5(+655.7(-1017() - characteristic of fracture toughness in plane deformation (MPa× m1/2);B - specimen thickness (mm); W- width of specimen (mm); P -cycle loading;a - initial crack length (mm).