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Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos

Abstract

When Inconel or Inor-8 alloys are exposed to a molten fluoride mixture containing reducible material, chromium is selectively oxidized and removed from the alloy. By the use of radio-tracer Cr{sup 51}, the self-diffusion coefficients for chromium in Inconel and Inor-8 and the applicability of these values to alloys under corrosive conditions have been evaluated. Overall coefficients have been obtained (1) by measuring depletion of Cr{sup 51} (charged as CrF{sub 2}) for non-corrosive fluoride melts in alloy capsules and (2) by comparison of measured total radioactivity of exposed alloy specimens with that of the salt to which they were exposed. In addition, coefficients were obtained from measurement of tracer concentration profiles through successive electropolishings of the specimens. The overall coefficients and those obtained from electropolishing experiments agree very well for Inconel at high temperatures and for Inor-8 at all temperatures. For temperatures below 750{sup o}C, coefficients obtained by electropolishing Inconel specimens are higher than the overall values; the bulk diffusion process is not uniform for this case. In all cases, good agreement was found between the overall diffusion coefficients and those extrapolated from published data at higher temperature with generally similar Cr-Ni alloys. Duplicate, polythermal loops of Inor-8 were used to  More>>
Authors:
Grimes, W R; Watson, G M; DeVan, J H; Evans, R B [1] 
  1. Oak Ridge National Laboratory, Oak Ridge, TN (United States)
Publication Date:
Mar 15, 1962
Product Type:
Conference
Resource Relation:
Conference: Conference on the Use of Radioisotopes in the Physical Sciences and Industry, Copenhagen (Denmark), 6-17 Sep 1960; Other Information: 8 figs, 1 tab., 16 refs; Related Information: In: Radioisotopes in the Physical Sciences and Industry. Proceedings of the Conference on the Use of Radioisotopes in the Physical Sciences and Industry. V. III| 652 p.
Subject:
07 ISOTOPES AND RADIATION SOURCES; CHROMIUM FLUORIDES; ELECTROPOLISHING; INOR-8; IRON FLUORIDES; MOLTEN SALTS; RADIOACTIVITY; SELF-DIFFUSION; TRACER TECHNIQUES
OSTI ID:
22025754
Research Organizations:
International Atomic Energy Agency, Vienna (Austria); United Nations Educational, Scientific and Cultural Organization, Paris (France)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA12N1770113047
Submitting Site:
INIS
Size:
page(s) 559-574
Announcement Date:
Jan 17, 2013

Citation Formats

Grimes, W R, Watson, G M, DeVan, J H, and Evans, R B. Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos. IAEA: N. p., 1962. Web.
Grimes, W R, Watson, G M, DeVan, J H, & Evans, R B. Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos. IAEA.
Grimes, W R, Watson, G M, DeVan, J H, and Evans, R B. 1962. "Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos." IAEA.
@misc{etde_22025754,
title = {Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos}
author = {Grimes, W R, Watson, G M, DeVan, J H, and Evans, R B}
abstractNote = {When Inconel or Inor-8 alloys are exposed to a molten fluoride mixture containing reducible material, chromium is selectively oxidized and removed from the alloy. By the use of radio-tracer Cr{sup 51}, the self-diffusion coefficients for chromium in Inconel and Inor-8 and the applicability of these values to alloys under corrosive conditions have been evaluated. Overall coefficients have been obtained (1) by measuring depletion of Cr{sup 51} (charged as CrF{sub 2}) for non-corrosive fluoride melts in alloy capsules and (2) by comparison of measured total radioactivity of exposed alloy specimens with that of the salt to which they were exposed. In addition, coefficients were obtained from measurement of tracer concentration profiles through successive electropolishings of the specimens. The overall coefficients and those obtained from electropolishing experiments agree very well for Inconel at high temperatures and for Inor-8 at all temperatures. For temperatures below 750{sup o}C, coefficients obtained by electropolishing Inconel specimens are higher than the overall values; the bulk diffusion process is not uniform for this case. In all cases, good agreement was found between the overall diffusion coefficients and those extrapolated from published data at higher temperature with generally similar Cr-Ni alloys. Duplicate, polythermal loops of Inor-8 were used to circulate a non-corrosive fluoride melt containing Cr{sup 51} (as CrF{sub 2}). One of these loops was sacrificed to evaluate take-up of Cr{sup 51} by the alloy; the second was used to circulate a melt containing FeF{sub 2} to obtain measurable removal of Cr from the alloy. Good agreement between observed behaviour and that predicted from the measured diffusion coefficients was obtained; this agreement suggests that the self-diffusion coefficient for Cr is insensitive to changes in chromium content of the Inor-8 alloy. (author) [French] Lorsqu'on soumet les alliages Inconel ou Inor-8 a l'action d'un melange de fluorures fondus contenant, des substances reductibles, le chrome est oxyde selectivement et elimine de l'alliage. En utilisant comme radioindicateur le chrome-51, les auteurs du memoire ont evalue les coefficients d'autodiffusion du chrome dans l'Inconel et l'Inor-8 et verifie dans quelle mesure les valeurs obtenues sont applicables aux alliages exposes a la corrosion. Les auteurs ont calcule les coefficients globaux: 1) en mesurant le passage du chrome-51 (employe sous forme de CrF{sub 2}) des capsules d'alliage aux fluorures non corrosifs fondus; 2) en comparant la radioactivite totale mesuree des echantillons d'alliage exposes avec celle du sel auquel ils avaient ete exposes. Ils ont calcule en outre des coefficients en mesurant les profils de concentration de l'indicateur par polissages electrolytiques successifs des echantillons. Les coefficients globaux et ceux qui ont ete obtenus par polissage electrolytique concordent parfaitement pour l'Inconel a des temperatures elevees et pour l'Inor-8 a toutes les temperatures. Pour les temperatures inferieures a 750{sup o}C, les coefficients obtenus par polissage electrolytique de l'Inconel sont superieurs aux coefficients globaux; dans ce cas, le processus de diffusion dans la masse n'est pas uniforme. Il y a toujours concordance satisfaisante entre les coefficients globaux de diffusion et les coefficients obtenus par extrapolation des donnees publiees au sujet d'alliages Cr-Ni generalement analogues, a des temperatures plus elevees. Les auteurs se sont servis de deux anneaux polythermiques d'Inor-8 pour faire circuler une masse de fluorures fondus non corrosifs contenant du chrome-51 (sous forme de CrF{sub 2}). Ils ont sacrifie l'un des circuits pour evaluer la quantite de {sup 51}Cr absorbee par l'alliage, et utilise l'autre pour faire circuler un melange fondu contenant du FeF{sub 2} et mesurer l'elimination du chrome de l'alliage. Les resultats obtenus concordent assez, bien avec les donnees fournies par les coefficients de diffusion mesures experimentalement; il est permis d'en conclure que le coefficient d'autodiffusion du chrome est insensible aux modifications de la teneur en chrome de l'alliage Inor-8. (author) [Spanish] Si se someten el Inconel o el Inor-8 a la accion de una mezcla de fluoruros fundidos, que contenga sustancias reducibles, el cromo sufre una oxidacion selectiva y es extraido de la aleacion. Con ayuda del indicador radiactivo {sup 51}Cr, los autores han evaluado los coeficientes de autodifusion del cromo en el Inconel y en el lnor-8, y han comprobado que los datos obtenidos son validos para las aleaciones expuestas a la corrosion. Han calculado los coeficientes globales 1) midiendo el paso del {sup 51}Cr de las capsulas de aleacion (empleado en forma do CrF{sub 2}) a los fluoruros no corrosivos fundidos, y 2) comparando la radiactividad total medida en las muestras de aleacion expuestas con la radiactividad de la sal a cuya accion fueron sometidas. Ademas, calcularon los coeficientes midiendo los perfiles do concentracion del indicador por pulidos electroliticos sucesivos de las muestras. Los coeficientes globales y los obtenidos por pulido electrolitico concuerdan satisfactoriamente para el Inconel a temperaturas elevadas, y para el lnor-8 a todas las temperaturas. Los valores obtenidos por pulido electrolitico del Inconel tratado a temperaturas inferiores a 760{sup o} C superan a los valores globales; en este caso, el proceso de difusion masica no es uniforme. Los coeficientes medios de difusion encontrados concuerdan siempre con los que se calculan por extrapolacion de los valores publicados, que fueron obtenidos con aleaciones de Cr-Ni similares, a temperaturas mas elevadas. Los autores se sirvieron de un par de buees politermicos de Inor-8 para hacer circular una masa de fluoruros no corrosivos fundidos que contenian {sup 51}Cr (en forma de CrF{sub 2}). Sacrificaron uno de estos bucles para evaluar la cantidad de {sup 51}Cr absorbida por la aleacion; el segundo se utilizo para hacer circular una mezcla fundida quo contenia FeF{sub 2} y medir la eliminacion del cromo de la aleacion. Los resultados obtenidos concuerdan satisfactoriamente con los que se calculan con ayuda de los coeficientes de difusion determinados experimentalmente; esta concordancia indica que el coeficiente de autodifusion del Cr no es afectado por las variaciones de la concentracion de cromo en la aleacion Inor-8. (author) [Russian] Kogda ''inkonel'' ili ''inor-8'' podvergayutsya dejstviyu rasplavlennykh ftoristykh smesej, soderzhashchikh vosstanavlivayushchie veshchestva, khrom izbiratel'no okislyaetsya i udalyaetsya iz splava. S pomoshch'yu radioaktivnogo indikatora Cr{sup 51} byli ustanovleny koehffitsienty samodiffuzii khroma v ''inkonsle'' i ''inore-8'', a takzhe byla izuchena primenimost' znachenij ehtikh koehffitsientov k splavam v korrozijnykh usloviyakh. Summarnye koehffitsienty byli polucheny putem sleduyushchikh zamerov: 1) obedneniya v Cr{sup 51} (zagruzhennogo v vide CrF{sub 2}) nekorrozijnykh ftoristykh rasplavov v legirovannykh kapsulakh i 2) sootnosheniya mezhdu izmerimoj obshchej radioaktivnost'yu obrabotannykh sol'yu obraztsov splava i radioaktivnost'yu soli, dejstviyu kotoroj obraztsy byli podvergnuty. Pomimo ehtogo, koehffitsienty byli polucheny putem zamera grafika kontsentratsii indikatora pri posledovatel'noj ehlektropolirovke obraztsov. Summarnye koehffitsienty, a takzhe koehffitsienty, poluchennye opytami ehlektropolirovki, ochen' blizko sovpadayut dlya ''inkonelya'' pri vysokikh temperaturakh i dlya ''inora-8'' pri vsekh temperaturakh. Dlya temperatur nizhe 750{sup o} C koehffitsienty, poluchetshe pri pomoshchi ehlektropolirovki obraztsov ''sinkonelya'' prevyshayut znacheniya summarnykh koehffitsientov; v ehtom sluchae protsess diffuzii v masse ne odnoobrazen. Vo vsekh sluchayakh nablyudalos' khoroshee sovladenie mezhdu summarnymi koehffitsientami diffuzii i koehffitsientami, poluchennymi putem ehkstrapolyatsii dannykh, opublikovannykh obychno dlya analogichnykh splavov khroma i nikelya pri bolee vysokikh temperaturakh. Dvojnye politermicheskie petli ''inora-8'' byli ispol'zovany dlya tsirkulyatsii nekorrozijnogo ftoristogo rasplava, soderzhashchego Cr{sup 51} (v vide CrF{sub 2}). Odna iz ehtikh petel' byla pozhertvovana dlya opredeleniya usvoeniya Cr{sup 51} ehtim splavom; vtoraya petlya byla ispol'zovana dlya tsirkulyatsii rasplava, soderzhashchego FeF{sub 2}, dlya polucheniya izmerimogo ustraneniya Cr iz splava. Bylo polucheno khoroshee sovpadenie mezhdu fakticheski nablyudavshimisya yavleniyami i prognozom, sdelannym na osnovanii izmerennykh koehffitsientov diffuzii. Iz ehtogo sovpadeniya mozhno zaklyuchit', chto koehffitsient samodiffuzii khroma nechuvstvitelen k izmeneniyam soderzhaniya khroma v splave ''inor-8''. (author)}
place = {IAEA}
year = {1962}
month = {Mar}
}