SUS304,SUS321および2 1/4Cr-1Mo鋼の高温および超高温引張試験

High and ultra-high temperature tensile tests on SUS304, on SUS304, SUS321 and 2.25Cr-1Mo steels

土田 豊*; 加藤 章一*; 平野 正敦*; 二瓶 勲*

not registered; not registered; not registered; not registered

SUS304鋼板材,SUS321伝熱管相当板材および鍛造材,および21/4Cr―1Mo鋼板材につき高温引張試験を行ない「もんじゅ」材料強度基準の短時間引張持性につきその妥当性を確認すると共に,SUS304鋼板材およびSUS321鋼伝熱管相当板材,鍛造材につき,ナトリウム-水反応恃を想定した高ひずみ速度での超高温引張試験特性(900まで)を評価した。主要結果は次の通りである。▲高温域(650以下)での引張持性▲1)SUS304鋼および21/4Cr―1Mo鋼の板材では,0.2%耐力および引張強さが「もんじゅ」設計降伏強さSyおよびSuを下廻ることはなかった。▲2)各鋼種の破断伸びおよび紋りは既存データと一致し,十分高い値を有していた。▲3)各鋼種の弾塑性パラメータはBDS式とほぼ同等な値を示し,BDS式の妥当性が確認された。▲超高温域(650900)での引張特性▲1)SUS304および321鋼伝熱管相当板材,SUS321鋼鍛造材につき,1および10%/minのひずみ速度で900までの超高温引張試験を行ない,引張強さ,0.2%耐力,破断および紋りのデータを取得した。▲各鋼種の破断伸びおよび紋りは優れた値を示し,またひずみ速度が大きい程高い延性を持つ傾向を示した。▲引張強さに対する引張ひずみ速度の影響を定量的に評価する試みを行ない,これを用いてSUS304鋼およびSOS321鋼のJISに準拠したひずみ速度での引張強さの推定(900まで)を試みた。▲

High temperature tensile tests were performed on SUS304, SUS321 and 2.25Cr-1MO Steel to verify the tensile properties of Materials Strength Standard for Monju. Tensile tests were also performed at ultra-high temperatures (up to 900C) on SUS304 and SUS321 steel plates and SUS321 steel forging. Evaluation of high temperature and high strain rate tensile properties which simulate the tensile condition of sodium-water reaction was made. Major results obtained are as follows: (1)Tensile properties of SUS 304, SUS321 and 2.25Cr-1Mo steel below 650C. (i)Tensile strength and 0.2% proof strength did not fall below the design tensile strength and design yield strength respectivety. (ii)Fracture elongation and reduction of area agreed well with those of references, and showed satisfactory values. (iii)Elasto-plastic paramaters were almost comparable with those for Monju design. This proves the validity of Elasto-plastic parameters for Monju. (2)Tensile properties of SUS304 steel plate, SUS 321 steel plate and forging at 650900C. (i)Tensile properties data (tensile strength, 0.2% proof strength, fracture elongation and reduction of area) were obtained up to 900C at strain rates of 1 and 10%/min. (ii)Fracture elongation and reduction of area of these steels were high enough, and improved as the strain rate increased. (iii)An attempt to evaluate the effect of strain rate on tensile strength was made. Applying this to the ultra-high temperature data at 110%/min, tensile strength under JIS high temperature test condition was estimated.