Strain Rate Effects of Nuclear Steels in Room and Higher Temperatures
An investigation of strain rate, temperature and size effects of three nuclear steels has been undertaken. The materials are: ferritic steel 20MnMoNi55 (vessel head), austenitic steel X6CrNiNb 1810 (Upper Internal Structure ), and ferritic steel 26NiCr Mol46 (bolting). Smooth cylindrical tensile specimens of three sizes have been tested at strain rates from 0.001/s up to 300/s, at room and elevated temperatures (400oC-600oC). Full stress-strain diagrams have been obtained, and additional parameters have been calculated based on them. The results demonstrate a clear influence of temperature, which amounts into reducing substantially mechanical strengths with respect to R.T. conditions. The effect of strain rate is also shown. It is observed that at R. T .the strain rate effect causes up-shifting of the flow stress curves, whereas at the higher temperatures a mild down-shifting of the flow curves is manifested. Size effect tendencies have also been observed. Some implications when assessing the pressure vessel structural integrity under severe accident conditions are considered.
Bibliographic Reference: An oral report given at: 16th International Conference on Structural Mechanics in Reactor Technology SMiRT16. Organised by: Prof. Ajaya Kumar Gupta, North Carolina State University (US). Held in: Washington DC USA, 12-17 August, 2001
Record Number: 200013408 / Last updated on: 2001-06-27
Original language: en
Available languages: en