1. Crack determination Made by Voronova O.Y. Scientific supervisor – Volchuc V.N. Language supervisor – Kuznecova E.S.

2. 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).

3. Fracture Ductile fracture Brittle fracture

4. General Information -Experimental determination of crack -structural features -specimen “compact” model -stress intensity

5. Fragility is not a property

6. The influence of structural features O brittle fractures; O larger grains of ferrite; O distribution of cementite (Fe3C); O impurities effect.

7. The effect of additives -oxygen,nitrogen,phosphorus, sulfur,silicon -vanadium,cobalt,chromium -manganese,copper,nickel

8. Standard sample Parameter of fracture toughness -is a property of material characterizes its viscosity or ability to slow down the destruction

9. Stress intensity

10. Thank you for your attention!