報告書番号

281050

タイトル（和文）

高温ナトリウム中における高速炉材料の腐食の調査

タイトル（英文）

ON CORROSION OF MATERIALS FOR LMFBR IN HIGH TEMPERATURE SODIUM

概要 （図表や脚注は「報告書全文」に掲載しております）

高速増殖炉の材料で高温ナトリウムに長時間接触する材料はナトリウムによって腐食される。ＡＳＭＥコードでは腐食による材料の劣化の評価法が定められていない。この報告は一般腐食と粒界腐食の調査を行ったものである。１）一般腐食：腐食速度はナトリウム温度，流速，酸素濃度に依存するが，腐食による厚さ減少は小さい。２）粒界腐食：粒界からの合金成分の選択的溶出によるもので，この結果粒界の材料強度が減少すると考えられる。

概要 （英文）

CONSIDERATION OF DETERIORATION OF MATERIAL CAUSED BY CORROSION IS GENERALLY OUTSIDE THE SCOPE OF THE ASME CODE APPLIED FOR DESIGN OF LMFBR.IN THIS CODE,THE RULES DO NOT PROVIDE METHODS TO EVALUATE DETERIORATION WHICH OCCURS IN SERVICE AS A RESULT OF CORROSION,MASS TRANSFER PHENOMENON,RADIATION EFFECTS OR OTHER MATERIAL STABILITY AND IT IS RESPONSIBILITY OF THE OWNER TO SELECT MATERIALS. IN THIS REPORT,GENERAL CORROSION AND INTERGRANULAR CORROSION TO BE CONSIDERED CAUSE OF CRACK INITIATION ARE SUMMERIZED. 1.GENERAL CORROSION. CORROSION OF THE MATERIALS FOR LMFBR IS AFFECTED BY SODIUM TEMPERATURE,FLOW RATE,OXYGEN CONCENTRATION.BUT BECAUSE OF SMALL GENERAL CORROSION RATE,DECREASE OF THICKNESS DUE TO CORROSION IS NEGLIGIBLE FOR DESIGN. HOWEVER,CORROSION BEHAVIOR OF THE FUEL CLADDING TUBE UNDER HIGH HEAT FLUX IS IMPORTANT FROM THE POINT OF THE PRODUCTION OF ACTIVE CORROSION PRODUCTS. 2.INTERGRANULAR CORROSION. INTERGRANULAR CORROSION OF THE MATERIALS IN HIGHTEMPERATURE SODIUM IS CAUSED BY SELECTIVE LEACHING OF THE ALLOYING ELEMENT AS NICKEL AND CHROMIUM THROUGH THE GRAIN BOUNDARY. AS IT IS CONSIDERED THAT GRAIN BOUNDARY STRENGTH IS REDUCED BY THE INTERGRANULAR CORROSION,THE STUDY ON THE CORROSION IS IMPORTANT.

報告者

キーワード