| Autor: |
Krasovskii, A. Ya., Fedosov, A. I., Vainshtok, V. A., Zelentsov, G. N., Kanashenko, E. M., Minkin, L. N., Znachkovskii, O. Ya., Kashtalyan, Yu. A., Nadezhdin, G. N. |
| Zdroj: |
Strength of Materials; April 1979, Vol. 11 Issue: 4 p331-338, 8p |
| Abstrakt: |
1.In the investigated range of temperatures and thicknesses of specimens of steel 15Kh2NMFA, the main reason for the nonlinearity of the fracture curves is not subcritical crack growth, but plastic strain of the material at the crack tip. Since crack advance is seen in the 12–50-mm-thick specimens only after loading above PQ, the value of KQ obtained by the standard method [1] characterizes not crack advance, but the condition of transition to intensive plastic flow in a specimen with a crack.2.Using structural steel 15Kh2NMFA as an example, it was shown that it is possible to use experiments with small laboratory specimens to predict the brittle fracture of large specimens in cases where fracture of the latter occurs without appreciable subcritical crack growth. By testing a series of small specimens, we may also investigate the crack resistance of different layers of a material to be used in a structure nonuniform through its thickness.3.It was established that the inner layers of the rolled plate of steel 15Kh2NMFA from the investigated heat exhibit a significantly higher density of nonmetallic inclusions than the outer layers, and the crack resistance and impact toughness of the latter are greater than for the former. The effect of material nonuniformity on crack resistance diminishes with decreasing temperature. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Full text from SpringerLink