Crack Paths 2006

C O N C L U S I O N S

After long-term operation of trunk pipelines, the resistance of the steels of the pipes to

brittle fracture decreases, first of all, the impact strength and resistance to hydrogen

cracking.

The effect of in service steel degradation of trunk pipelines is connected with the

combined action of exploited stresses and hydrogen absorbed by metal from the

technological environments and can cause the anisotropy of its the brittle fracture

resistance, especially, impact strength.

Inspection of the presence of surface defects and damages only is insufficient for the

substantiation of serviceability. It is also necessary to evaluate the possible changes in

mechanical properties, first of all, resistance to brittle fracture.

R E F E R E N C E S

1. Slobodyan Z.V., Nykyforchyn H.M. and Petrushchak O.I. (2002) Material Science.

3, 424-429.

2. Krasowsky, A.Y., Dolgiy, A.A. and Torop V.M. Proc. “Charpy Centary

Conference”, Poitiers. (2001) Vol. 1, 489-495.

3. Slobodyan, Z., Petrushchak, O., Nykyforchyn H. and Lunarska, E. (2002)

Physicochemical Mechanics of Materials, special issue 3, 782-785.

4. Chernov V.Yu., Makarenko V.D., Kryzhanivs’kyi E.I. and Shlapak L.S. (2002)

Material Science 6, 880-883.