国産ODS材腐食評価試験

Corrosion tests for evaluation of corrosion resistance of domestic oxide dispersion strengthened ferritic steels

湯谷 順明*; 細川 隆徳*; 山中 庸靖*

Yutani, Toshiaki*; not registered; not registered

国産ODS管材(13Cr-0.5Y2O3-0.5Ti-3Wおよび11Cr-0.25Y2O3-0.5Ti-2W)および高強度フェライト/マルテンサイト管材1FKの腐食特性を把握するため、改良SUS316管材をレファレンス材とし、テルルおよびヨウ素を腐食剤として、温度500、600および700度C、時間100hの条件で腐食試験を行い、以下の結果を得た。(1)テルルに対する耐食性は試験温度700度Cでは、改良SUS316に比較して13Cr-0.5Y2O3-0.5Ti-3Wは優れていたが、11Cr-0.25Y2O3-0.5Ti-2Wと1FKは劣っていた。(2)試験温度500および600度Cでは、Cr含有量が高いほどテルルに対する耐食性が高くなる傾向が認められた。(3)ヨウ素による腐食試験で重量損失が認められ、4供試材とも重量損失は600度Cで最大であった。(4)改良SUS316に比較して、13Cr-0.5Y2O3-0.5Ti-3W、11Cr-0.25Y2O3-0.5Ti-2Wおよび1FKのヨウ素に対する耐食性は劣っている。

Corrosion tests with tellurium and iodine were conducted at 500, 600 and 700C for 100 hours, to evaluate corrosion resistance to fission products. Domestic oxide dispersion strengthened ferritic steel tubes (13Cr-0.5YO-0.5Ti-3W steel and 11Cr-0.25YO-0.5Ti-2W steel), high strengthened ferritic/martensitic steel tube (1FK) and modified SUS316 stainless steel tube were tested. The results were summarized as follows. (1)13Cr-0.5YO-0.5Ti-3W steel was superior to and 11Cr-0.25YO-0.5Ti-2W steel and 1FK were inferior to the modified SUS316 stainless steel in corrosion resistance to tellurium at 700C. (2)It was recognized that corrosion resistance to tellurium improved with chromium content at 500 and 600C. (3)All steel specimens had the highest weight losses at 600C in the corrosion tests by iodine. (4)13Cr-0.5Y0-0.5Ti-3W steel, 11Cr-0.25YO-0.5Ti-2W steel and 1FK were inferior to the modified SUS316 stainless steel in corrosion resistance to iodine at 600C.