NDT温度に及ぼすクラックスタータービード溶接の影響に関する研究(昭和60年度秋季全国大会論文発表講演論文)

概要

論文の詳細を見る
In ASME Code Sec. III, the value of the reference nil-ductility temperature RT_<EDT> has an important significance to determine the result of the fracture mechanics evaluation. While in the standard both the drop-weight test and Charpy impact test are required to determine the RT_<NDT>, in practice it is normally determined only by the nil-ductility transition temperature (T_<EDT>) obtained by the drop-weight test. The causes of data scatter in T_<NDT> were investigated to establish appropriate conditions of crack-starter bead welding. Drop-weight tests were carried out for nuclear vessel steels by changing welding conditions to examine the effects of welding amperage and shapes of welding table on T_<NDT>. The results show that the preparation of crack-starter bead by small welding amperage should not be allowed, because it makes the measured T_<NDT> non-conservative, and that it is important to use a welding table which increases the cooling rate of specimen. Furthermore, the authors proposed methods for estimating T_<NDT> of nuclear vessel steels by using Charpy transition temperatures.
1985-08-05