| Autor: |
Girenko, V. S., Deinega, V. A., Khololeev, A. M. |
| Zdroj: |
Strength of Materials; November 1971, Vol. 3 Issue: 11 p1274-1280, 7p |
| Abstrakt: |
Conclusions 1.In evaluating the viscosity of structural steels from the standpoint of fracture mechanics, it is necessary to take into account the local changes in the properties of the metal that occur during formation of specific initial defects, including fatigue cracks.2.The cyclic deformation cumulative ahead of a fatiguecrack front and the deformation aging of the metal in these zones materially alter the initial viscosity of low-carbon and low-alloy steels. The character of these changes depends on the preliminary cyclic loading regime and especially on the aging rate and the tendency of the material toward aging.3.Deformation aging of low-carbon steels and low-alloy steels with a tendency to age reduces their fracture strength, as manifested in an increase in the lower critical temperature and a considerable decrease in the critical crack width in the quasibrittle range. Cyclic cold working (without aging) under similar conditions leads to a temporary increase in the viscosity of the metal, as a result of a rheotropic inversion effect. Aging must therefore be considered as an obligatory procedure in testing materials with a tendency toward this process.4.The linear relationship established by some authors between the logarithm of the critical crack width and the reciprocal test temperature [11, 12] was found to be lacking for some materials. As a result, it is premature to conduct tests on different classes of steels on the basis of the assumed existence of such relationships. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Full text from SpringerLink