熱応力緩和構造モデル(1)供試体熱過渡強度試験; 第3報,供試体の材料供強度

Creep fatigue test of thermal stress mitigation structure model (1) Under thermal transient loadings; (3) Mechanical properties of the test model materials

田中 信之*

not registered

本試験は熱応力緩和構造モデル(1)供試体と同一仕様の材料(SUSF304, SUS304TP及びSUS304)を用いて、疲労試験及びクリープ試験を実施し、「高速原型炉高温構造設計方針材料強度基準等」の最適疲労破損式からの偏差の調査及びクリープひずみ式ならびに主クリープ破断関係式の適合性を調査する事を主たる目的として実施したものである。さらに非弾性解析を実施するにあたって繰り返し応力-ひずみ関係の平均的挙動に対する偏差の調査も合わせて行った。本試験結果から熱応力緩和構造モデル(1)供試体に用いた材料は板材のクリープ強度がやや高目であった事を除いて、疲労強度、クリープ強度共にSUS304の平均的強度を有すること、また繰り返し応力―ひずみ関係、クリープひずみも平均的挙動を示すことが明らかとなった。したがって板材(供試体ではスリット入り円筒胴に使用)を除き、非弾性解析及びクリープ疲労損傷評価を実施する場合、現行の材料強度基準等が適用できる。

This study was carried out in order to examine the basic mechanical properties of the materials (SUSF304, SUS304TP and SUS304) which had the same specifications as was used for fabricating the Stress Mitigation Structure Model (1) Fatigue and creep tests were conducted and the results were compared with the best fit curve fatigue failure, creep strain equation and creep rupture equation of the material strength standard for "Monju". Besides, stress-strain curves at the steady state load cycle were compared with the standard bi-linear stress-strain relationship installed in FINAS, The results are surmmarized as follows. The materials had almost the same value for both fatigue failure strength and creep rupture strength as the average trend value of the material strength standard for "Monju". except for the creep rupture strength of the plate material which showed rather higher value. Besides, cyclic stress-strain curves and creep strain behavior showed nearly the same tendency as the standard or FINAS data. So, it should be said that inelastic thermal strees analysis and creep-fatigue damage evaluation can be done by usjng the average standard values described in the material strength standard for "Monju".