OAK RIDGE NATIONAL LABORATORY operated by UNION CARBIDE CORPORATION for the U.S. ATOMIC ENERGY COMMISSION ,/ VAR ORNL- TM- 411 ~ | _* g CORROSION OF NICKEL-BASE SPECIMENS EXPOSED IN THE . & VOLATILITY PILOT PLANT MARK 11l FLUORINATOR " - B L 1“ o a p M. Kegley, Jr. P T. A. P, Litman 2 4 2 DS WY A LI L 2T T P RS S el R IS ) ' “ : it N s i- ?‘O “ 5 p 3 ./.‘ C e y Roy E ' e | 7 NOTICE This document contains information of a preliminary nature and was prepared primarily for internal use ot the Ock Ridge National Laboratory. It is subject to revision or correction and therefore does not represent a final report, The information is not to be abstracted, reprinted or otherwise given public dis- semination without the approval of the ORNL patent branch, Legal and Infor- mation Control Department, LEGAL NOTICE This report was prepored os an account of Gavernment sponsored work, MNeither the Unired States, nor the Commission, noer any person acting on behclf of the Commissien: A, Makes any worranty ar represaniation, expressed or implied, with respect to tha wccuracy, completeness, or usefulness of the information contained in this report, or that the use of ony information, apperatys, method, or process disclosed in this report may not infringe privately owned righis; or B. Assuymes ony liabilities with respect to the vse of, or for domages resulting from the use of any information, apparotus, method, or orocess disclosed in this repart, As used in the cbove, “‘person acting on behalf of the Commission® includes any employee or controctor of the Commission, or employee of sueh contractor, to the extent that such employes or contractor of the Commission, or employeo of such contractor prepares, disseminates, or provides access to, any information pursuant to his employment or contract with the Cammission, or his employment with such contractar, ORNL-~TM=-411 Copy,.2 / Contract No. W-7405-eng-26 METALS AND CERAMICS DIVISION CORROSION OF NICKEL~-BASE SPECIMENS EXPOSED IN THE VOLATILITY PILOT PLANT MARK IIT FLUORINATOR T. M. Kegley, Jr., and A. P. Litman DATE ISSUED JAN 4 1963 OAK RIDGE NATTONAL LABORATORY Oak Ridge, Tennessee operated by UNION CARBIDE CORPORATION for the U. S. ATOMIC ENERGY COMMISSION ii CONTENTS INTRODUCTION ===- = e mm e e e e e e e e e e e e e e m e —m e EXPERIMENTAL PROCEDURE -=-=----—me e e e e e e e e e o Specimen Description —---cesmmmmmmmm e e e Test Method ~wwecmmmmmm e e - Test Conditions =--=--meemcce e e e e e e RESULTS =--==-emmm e m e e e e e e e e e e e m e e — Visual Examination ------=-m--ccmmmmmm e - Dimensional Changes ~---=-—=-cm-mmo e e me e Metallographic BExamination -—-----ec-omeommcmcmcm e Surface FIlms =--------- e e e - Surface Attack -------remmmm e Intergranular Attack ---------mmmmmmmmm e Grain-Boundary Modifications ==w=ecc-mmmommmcm e Bend Tests ~emmemcmmm e e e e e - SUMMAYY === == e e e e e ;e —cme—m = ——— DISCUSSION OF RESULTS ==r--meeer e e e e e e e e e e e e m e e e - Comparison Between Group I and Group II Specimens -------- Comparison With Previous Studies ------——cmmmmmmmccmmee oo Effect of Fluorine Conditioning on L Nickel and INCO-61 Weld Metal =~-~-memmmmm e e CONCLUSTIONS ===m=mmem e e e e e e e e e e e e e e m e mm ACKNOWLEDGMENT ~-~—-mmme e e mm e e e e e e m e e — e APPENDTX -----m e e e e e e m e e e e e - o CORROSTON OF NICKEL-BASE SPECIMENS EXPOSED IN THE VOLATILITY PTLOT PLANT MARK ITI FLUORINATOR T. M. Kegley, Jr., and A. P. Litman TNTRODUCTION For several years the Volatility Pilot Plant has demonstrated the Teasibility of processing zirconium-base fuels using fluoride volatility technigues. In an INOR-8 hydrofluorination vessel, rejected fully en- riched zirconium-uranium alloy or dummy Zircaloy-Z2 fuel elements are dissolved at 500-600°C in NaF-LiF-ZrF, salts using an excess of anhy- drous HF gas. Zirconium and uranium metal are converted to soluble tetrafluorides which subsequently are transferred, along with the fluoride bath, to a fluorination vessel. In the [lucrinator, which is constructed of L nickel and operated at 500°C, elemental fluorine converts UF, to UFg product which ie decontaminated and collected in cold traps. Figure 1 shows a simplified Tlowsheet of the volatility process, Severe corrosion of the L nickel fluorinator occurs during processing. Three fluorinators have been used to date in the pilot plant, and all three have sustalned a maximum corrosion attack of approximately 1 mil/hr, based on the fluorine exposure times.1»? Efforts to reduce the corrosive attack on fluorination vessels have included minimizing the operating temperature, careful exclusion of sulfur-containing compounds, and the search for a more resistant construction material, Acceordingly, in the first two pilot plant fluorinators, Mark T and II, corrosion tests were periormed using many potential container materials, mostly nickel-bacse alloys.3 1A, P. Litman and A. E. Goldman, Corrosion Associated with Fluorina- tion in the Oak Ridge National Laboratory Fluoride Volatility Process, ORNL-2832, p 25 {June 5, 1961). A, P, Litman, Corrosion of Volatility Pilot Plant Mark I INOR-8 Hydrofluorinator and Mark IIT L Nickel Fluorinator After Fourteen Dissolution Rung, ORNL-3253, pp 1, 30 (Feb. 2, 1962). *A. P. Litman and A. E. Goldman, op. cit., pp 108-23. UNCLASSIFIED ORNL-LR-DWG 81615 Fa DISPOSAL I DESORPTION /. IN, NaF g "N d QUTLET UFg COLD | F2 AG. KOH SPRAY NGF -LiF-ZrFa ABSORPTION Fp TOWER Ha OUTLET ! UFe NEUTRALIZER MO;Q%FE COLLECTION l (10% KOH ) = I ARSORBER QUID WASTE 400 - o LI LIQUID HF + Hp o-io07C WASTE "FUEL CHARGING : Hp CHUTE F2 FREEZE VALVE ) : — B HF : ! 5 &GF"L%?"'“Z.FF% RECYCLE k\ J SYSTEM L / ot/ NaF -Lif-ZrF4-UFy \ ( ‘ WASTE SALT Zru i ?v1 e q SPENT PO 1 £ o : | 1 | ! i FUEL ~ . 1| 1 s00%c | ! L o ! | 1 850-50Q C ¢ P s/ ] E PN i e HF FREEZE o - HYDROFLUORINATOR Fig. 1. Simplified Flowsheet — ORNL Fluoride Volatility Process, -3 - Those nickel binaries containing iron, cobalt, or manganese showed improved corrosion resistance over L nickel and were thus selected for additional testing in the current Mark IIT Tluorinator. To date, 24 specimens have been exposed in the Mark III fluorinator. This report covers the 12 specimens comprising Groups I and IT. Groups III and TV will be discussed in a separate report. In addition, specimens have been placed in the Tluorinator Tor exposure during current runs where irradiated submarine fuel elements are being processed. EXPERTMENTAL PROCEDURE Specimen Description Desceriptions of the Group I and IT test specimens, their location, and chemical compositions are shown in Tables 1 and 2. Control specimens contalning the materials used in the construction of the tTluorinator were included in both groups. The control specimens consisted of Z-in. lengths of £-in.-diam L nickel rod joined together with %-in. deposits of INCO-tl weld metal. The control specimen Trom Group I and one of the controls from Group II were fluorine conditioned for 3.2 hr at 600-645°C before testing to ascertain the effsct of conditioning on corrosion. The high-purity, vacuum-melted nickel specimen was obtained by re- melting NiVac P nickel. Bubsequently, the high-purity nickel was cast into a l-in.-diam bar, cold swaged and cold drawn down to an C.250-in. rod, and annealed at 1500°F. The other binary alloys used in these tests were melted from virgin stock and cast into l-in.-diam bars, cold swaged and cold drawn down to 0.250-in. rods. Subsequently they were annealed at 1650°F and placed in test. Test Method The specimen rods were located in nozzles attached to the lower chamber of the Mark IIT Tluorination vessel, as shown in Fig. 2. Hach rod was held in place by a fitting which gripped a tube prewelded to the end of the rod (see Fig. 3). TFigure 4 shows a polar view of the fluorina- tion chamber and the plan layout of the corrosion nozzles. Table 1. Test Specimens Exposed in the Volatility Pilot Plant Mark TIII Nickel Fluorinator Specimen Nozzle No. Location Description& Group 1 51 0 L nickel, 3-in. lengths, Jjoined by INCO-61 weld metal 32 L 98 NWi—-2 Mn 39 P High-purity, vacuum-melted nickel 24R R 95 Ni-5 Fe 27 M 90 Ni-10 Fe 29 N 80 Ni~20 Fe Group II 52 P L nickel, 3-in. l@ngthg, Joined by INCO-61 weld metal 55 N L nickel, 3-in. lengths, joined by INCO-61 weld metal® 17 0 95 Ni~5 Co 21 R 90 Ni-10 Co 1R M 99 Ni—1 Al 5 L 97 Ni—-3 Al a All rods spproximately (0.250 in. diam X 36 in. long. DControi specimen — Tluorine conditioned for 5.3 hr at 560-670°C. C . C o | Contrcl specimen — not conditioned. Table 2. Chemical Analyses of Test Specimens Welght Percent {ppm) Material Ni Mn Fe Co Al Sd Ti C S 98 Ni—Z2 Mn $7.00 2.18 0.057 40 95 Ni—5 Fe 95 4.9 0.019 < 10 90 Ni-10 Fe 88 11.8 0.0i6 < 10 80 Ni—20 Fe 79.6 20.1 0.017 < 10 95 Ni—5 Co 9. 6 5.9 0.020 < 10 90 Ni—-10 Co 90.0 9.4 0.026 20 99 Ni-1 Al < 0.04z2 < 10 97 Ni-3 Al 96.4 3. 0.027 < 10 INCO-61 weld 96+ 0.26 0.35 1. .36 1.44 0.0z27 30 metal deposit NivVac P high- < 0.002 0,03 0.09 0.005 0. 007 purity Ni® L nickel® 99.0° min 0.35 0.40 0.35 0.0z 100 max f7race amounts of Cr, Ca, (u, Mg, and Op. D . . Noeminal analysis. “Including cobalt. R UNCLASSIFIED ORNL-LR-DWG 39150 -R FURNAGE LINER--—| | —FLUORINATION CHAMBER (16-in.0D) DRAFT TUBE —~—i_ WASTE SALT OUTLETMWig RINE INLET o INCHES FURNACE Fig. 2. Mark III Volatility Pilot Plant Fluorinator Vessel Showing Corrosion Specimen Nozzles. MECHANICAL THREADED Y/o-in. SCHED-40 PIPE UNCLASSIFIED CRNL-LR—DWG 70683 TUBE PRE-WELDED TO SPECIMEN -7 770 FIT THREADED FITTING FITTING TOP OF FLUCRINATION / CHAMBER (8 in. LONG) o SEAL WELD SPEcaMEN/ ,7///////////////////////\ Fig. 3. Method for Holding Specimen Rods in Fluorinator Vessel. UNCLASSIFIED ORNL-LR-DWG 70690 FLUORINE DRAFT TUBE —_ 0 O .~ SALT INLET CONNECTING CYLINDER BETWEEN SOLIDS SETTLING CHAMBER AND FLUORINATION CHAMBER — SALT QUTLET | O . Q Fo INLET T~ SALT SAMPLER NOZZLE Fig. 4. Polar View of the Top of the Fluorination Chamber Showing Location of Corrosion Specimen Nozzles. - 9 - Test Conditions The Group I corrosion specimens weres exposed during Volatility Pilot Plant runs T-1 thrcough T-7, while the Group II specimens were cxposed in rung TU-1 through TU-5. Test conditions Tor these runs are summarized in Table 2. The T runs were made without uranium in the system, while the TU runs were conducted with 0.3 wt % U in the starting fuel element. Table 3. Process Conditions for Groups I and II Corrosion Specimens Group Ea Group I1 Volatility Pilot Plant Runs T-1 through TU-1 through T-7 TU-5 Thermal cycles, room tempera- 7 5 ture fo operating temperature Salt composition, mole % LiF-NaF—2ZrF., LiF-NaF-ZrF, (~ 30~27—43) (~ 29-29-42) + 0.2 wt % U Molten salt exposure Time 267 nr 205.5 hr Temperature 485-605°C 490-575°C . b Filuorine exposure Time 12.0 hr 10.5 hr Temperature 535-570°C 500-515°C Fluorine input 5760 liters 5385 liters UFg exposure None 256 liters a'L nickel and INCO-61 weld metal specimen 51 was fluorine conditioned for 5.3 hr at 600°C (before exposure to Group I process conditions). v 0 . . Molten salt was also present during fluorine exposure. RESULTS Vigual Examination Visual examination of the Group I specimens disclosed fluoride salts had preferentially adhered to the specimens in the vapor and salt-vapor interface regions. Figure 5 shows the Group T specimens after cleaning with an ammonium oxalate solution. Burface roughening was apparent in all the specimens, but no gross localized metal losses were evident, Salt-vVapor UNCL ASSIFIED Y-38615 Fig., 5. Reduced 25%, Interface Level Group I Corrosion Specimens from Mark IIT Fluorinator. el Ixanmination of the Group II specimens showed flucride salts had preferentially adhered to specimens in the lower vapor region. Some loosely adherent deposits were alsco noted in the Interlace regilon. Figure 6 shows the Group II specimens after an ammonium oxalate wash. Dimensional Changes Bulk metal losses from the specimens were determined from micrometer measurements taken in the vapor, vapor-salt interflace, and salt-exposure regions. Table 4 details the results. The Group II specimens generally showed losses several times greater than the Group I specimens. Metallographic Examination Transverse and longitudinal sections taken from the vapcr, interface, and salt regions of the corrosion specimens were examined using optical microscopy. Photomicrographs of most of these gections are included in the Appendix. Metallographic examination revealed that corrosion had resulted in the production of one or more of the follewing: (1) surface Tilms, (2) surface attack, {3) intergranular attack, and (4) grain- boundary modilications. Surface Films Twe types of surface films were observed - a gray nonmetallic and a bright semimetallic film. Usually the films were intermittent in coverage rather than continuous. Figure 7 illustrates the types of fllms found. Details regarding the surface films Tound on the specimens are summarized in Tables 5 and ©. Except for the Group I specimens shewing a propensity Tor formation of bright films in the salt-exposed region, no particular pattern associating film Tormation with region of expcsure of specimen composition was obvious. Samples of the two types of surface Tilms were obtained from an L nickel specimen using a microchisel® and submitted for x-ray diffraction analyses. A quantitative analysis could not be cobtained, but the results, “G. L. Kehl, H. Steinmetz, and W. J. McGonnagle, Metallurgia 55(329), 151 (1957). T UNCL ASSIFIED ¥-40715 G e e et > M‘m‘ aasy e P MO, 55 LT MICKEL AND INCO 61 WELD METAL B LTOHICKEL AND INCO &) e B ) NGO, 52 'L Froconditioned with Fq' B A 1 o oo T en— m " i e NO.WZ ONI-95 CO -5 o ho M-S0 CO -1 SALT-VAPUR MITERFACE LEVELS ! WELD METAL Wwo. LR M- 99 AL R o NO. 5 ™M .97 AL-3 . g Rk ki Fig. 6. Group II Corrosion Specimens from Mark ITII Fluorinator. Reduced 22%. - 13 - Table 4. Bulk Metal Losses for Groups I and II Corrosion Specimens Vapor Salt Interface Vapor Region Region Salt Region Specimen _— No. Composition Max Av Max Av Max Av Group I 512 L nickel 1.4 0.9 2.0 1.7 2.2 1.5 INCO-61 weld metal 2.6 1.4 2.2 1.9 2.3 2.0 39 High-purity nickel 2.0 0.9 3.1 1.7 1.4 0.8 32 98 wt % Ni-2 wt % Mn 2.0 1.4 1.9 1.7 1.7 1.5 24R 95 wt % Ni—5 wt % Te 1.7 0.9 1.4 1.3 2.1 1.7 27 90 wt % Ni—-10 wt % Fe 1.9 1.1 1.8 1.5 1.7 1.4 29 80 wt % Ni—20 wt % Fe 2.9 1.4 1.4 1.0 1.9 1.6 Group TT 558 L nickel 2.9 1.75 9.1 8.4 7.1 5.9 INCO-61 weld metal 5.4 4.8 12.1 12.0 13.4 12.4 55b L nickel 2.7 2.4 11.4 8.9 7.1 6.3 INCO-61 weld metal 4,0 1.9 13.5 11.95 7.3 7.1 17 95 wt % Ni—5 wt % Co no change 13.4 10.5 11.9 9.2 21 20 wt % Ni~10 wt % Co 4.1 1.1 16.3 14.1 13.0 8.1 1R 99 wt % Ni—-1 wt % Al 2.3 1.2 11.5 10.6 7.8 6.3 5 97 wt % Ni—3 wt % Al 3.5 1.6 17.2 12.3 8.3 7. %control specimen fluorine conditioned 5.3 hr at 560-670°C. bControl specimen not conditioned. - 14 - N W T L3 = 002 NON-ME TALLIC § GRAY FILM 004 NICKEL SFPECIMEN 008 008 - O w-o... «©) (@) UNCLASsIFIED 2% . Y-39311 o po Lo e g NICKEL PLATE ™ .06 007 .008 209 BRIGHT FILM - Moy BN e P Sty ¢ «\_‘fl_ Ao & /’ \ . 010 L 1 011 / - = \\, . ! .al2 NICKEL SPECIMEN 013 014 (b) Fig. 7. Surface Films Found on Nickel Corrosion Specimens Exposed in Volatility Pilot Plant Mark TTIT Fluorinator. (a) Gray nonmetallic film found in vapor region of Group I L nickel specimen 51. 500X. (b) Semimetallic bright film found in salt region of Group I high-purity nickel specimen 39. Note intergranular attack. BSurface was nickel plated to preserve corrogion product, 250X. - 15 - Table 5, Surtace Films Found on Group I Volatility Pilot Plant Fluorinator Test Specimens Gray Nommetallic Film Bright Semimetallic Film specimen Maximum Thickness Maximum Thickness No. Description Region (mils) (mils) 51B L nickel Vapor Intermittent, 3.5 Nil Interface Nil Intermittent, 1.5 Salt Nil Intermittent, 1.0 51W INCO-6l Vapor Nil Nil weld Interface Nil Intermittent, 0.5 Salt Nil Continuous, 1.5% 39 High-purity Vapor Intermittent, 2.7 Nil nickel Interface Nil Intermittent, 1.0 Salt Nil Continuous, 1.2° 32 K nickel Vapor Intermittent, 1.2 Intermittent, 0.4 98 Ni—-2 Mn Interface Intermittent, 1.5 Intermittent, 0.2 Salt Nil Intermittent, 0.2 24R 95 Ni-5 Fe Vapor Nil Intermittent, 0.3 Interface Intermittent, 0.3 Intermittent, 0.2 Salt Nil Intermittent, 1.0 27 90 Ni-1Q Fe Vapor Intermittent, 1.2 Intermittent, C.1 Interface Nil Intermittent, OC.1 Salt Nil Intermittent, 0.8 £9 80 Ni~20 Fe Vapor Intermittent, 0.5 Intermittent, 0.2 Interface Nil Intermittent, 0.7 Salt Nil Intermittent, 0.2 a , . g . a . . cemimetallic film was continuous only on one sgide of longitudinal section. b . R . Semimetallic film was continucus over 60% of transverse section. - 16 - Table ©. Surface Films Found on Group II Volatility Pilot Plant Fluorinator Test Specimens Gray Nonmetallic Film Bright Semimetallic Film Specimen Maximum Thickness Maximum Thickness No. Description Region (mils) (mils) 52B L nickel Vapor Intermittent, 1.0 Intermittent, 0.1 conditioned Interface Intermittent, 0.3 Intermittent, 0.2 Salt Intermittent, 0.7 Nil 52W INCO-61 Vapor Intermittent, 1.3 Nil conditioned Interface Intermitient, 0.5 Intermittent, 0.2 Salt Nil Nil 55B L nickel Vapor Nil Intermittent, O.4 not condi~ Interface Nil Intermittent, 0.4 tioned Salt Nil Intermittent, 0.2 55W INCO-61 Vapor Intermittent, 0.4 Intermittent, 0.4 not condi- Interface Intermittent, 0.2 Nil tioned Salt Intermittent, O.Z Nil 17 95 Ni—5 Co Vapor Intermittent, 1.8 Intermittent, 0.7 Interface Nil Nil Salt Nil Nil 21 90 Ni—10 Co Vapor Nil Nil Interface Intermittent, 0.5 Nil Salt Nil Nil 1R 99 Ni-l1 Al Vapor Nil Intermittent, 0.1 Interface Intermittent, 0.5 Intermittent, 0.3 Salt Intermittent, O Nil 5 97 Ni—3 Al Vapor Intermittent, 0.7 Intermittent, 0.9 Interface Nil Nil Salt Nil Intermittent, 0.2 - 177 - Table 7, indicated the gray nonmetallic {ilm was mostly NiFp, while the bright semimetallic film was largely a mixture of NiC and nickel metal. Table 7, X-Ray Diffraction Analysis of Surface Films from L Nickel Specimen 51 Surface Pilm o Line Type Location Tdentified Intensity Gray, Vapor NiF» Strong nonmetallic reglion NiO Weak LiF Weak Bright, Salt NiQ© Medium semimetallic region Ni Medium fnidenti fied extra lines also present in both samples. Surface Attack Many of the corrosion specimens examined showed an attack of varying character which generally could not be categorized under any heading except surface attack. Occasionally tThis surface attack had the appearance of pitting~-type corrosion. Some typical examples of the types of surface attack found are shown in Fig. €. Additional photomicrographs showing surface attack are presented in the Appendix. Tntergranular Attack Intergranular attack was found in many samples from the corrosion specimens. Figure 7 illustrates this mode of corrosion as found on L nickel. The amount of intergranular attack observed on all specimens is recorded in Tables & and 9. In all cases corrosion resembling inter- granular attack was designated as such only 1T the attack was observed in the "ag-polished" metallographic condition. Grain-Boundary Modifications In some of the luorinator specimens, grain-boundary modifications occurred which differed Irom Intergranular attack as previously delined,. This form of grain-boundary attack was not apparent in the "as-polished" metallographic sections as was the case for intergranular attack. but was - 18 - UNCL ASSIFIED Y-44672 # UNCL ASSIFIED Y -44680 - B UNCL ASSIFIED Y-4484) (¢) f UNCL ASSIFIED : Y-44642 (d) 008 008 Fig. &. Surface Attack Found on Volatility Pilot Plant Fluorinator Test Specimens, Group II. (a) Vapor region of 99 Ni—L Al specimen 1R. (b) Vapor region of 97 Ni~3 Al specimen 5. (c¢) Vapor region of conditioned INCO-61 weld of specimen 52. {d) Interface region of conditioned INCO-61 weld of specimen 52. 300X. o e e o Table 8. Corrosion of Group I Volatility Pilot Plant Fluorinator Test Specimens Maximum Maximum Maximum Bulk Metal Surface Intergranular Total Specimen Attack Attack Attack Attack No. Material Region (mils) (mils) (mils) (mils) 51 L nickel Vapor Q.7 0.5 1.2 conditioned Intervace 1.0 1.5 2.5 Salt 1.1 4.5 5.0 51 IBCO~-61 Vapor 1.3 1.3 weld conditioned Interface 1.1 0.2 1.3 Salt 1.2 2.0 3.2 39 High-purity Vapor 1.0 0.2 1.2 nickel Interface 1.6 5.0 6.6 Salt 0.7 6.5 7.2 32 E nickel Yapor 1.0 0.3 1.3 98 Ni—2 Mn Interface 1.0 1.0 Salt 0.9 .9 24R 95 Ni~5 Fe Vapor 0.9 0.5 1.4 Interface 0.7 0.1 0.8 Salt 1.1 0.7 1.8 27 90 Ni-10 Fe Vapor 1.0 0.3 1.3 Interface 0.9 0.3 1.2 Salt 0.9 0.3 1.2 29 80 Ni—20 Fe Vapor 1.5 0.7 2.2 Interface 0.7 1.0 1.7 Salt 1.0 0.7 1.7 - 20 - Table 9., Corrosion of Group II Volatility Pilot Plant Fluorinator Test Specimens Maximum Maximum Maximum Bulk Metal OSurface Intergranular Total Specimen Attack Attack Attack Attack No. Material Region (mils) (mils) (mils) (mils) 52 L nickel Vapor 1.5 2.0 3.5 conditioned Interface 4.6 3.0 7.6 Salt 3.6 4.5 8.1 52 INCO-61 Vapor 2.7 1.0 3.7 weld conditioned TInterface 6.1 0.5 6.6 Salt 6.7 6.7 55 L nickel Vapor 1.4 3.0 A not condi- Interface 5.7 6.0 11.7 tioned Salt 3.6 5.0 8.6 55 INCO-61 Vapor 2.0 0.2 2.2 weld not condi- Interface 6.8 6.8 tioned Salt 3.7 3.7 17 95 Ni~5 Co Vapor 1.0 1.0 Interface 6.7 4.5 11.2 Salt 6.0 5.0 11.0 21 90 Ni—-10 Co Vapor 2.1 2.1 Interface 8.2 8.2 Salt 6.5 0.3 6.8 1R 99 Ni—-1 Al Vapor 1.2 0.5 1.7 Interface 5.8 5.8 Salt 3.9 3.9 5 97 Ni—3 Al Vapor 1.8 0.9 2.7 Interface 8.6 0.5 9.1 Salt 4.2 4,2 - 21 - visible when the sections were etched with 3 parts CH3;COOH and £ parts HNO3. The modifications were found to be more clearly defined if the etched surface was then ligntly repolished on a microcloth wheel using 0.1 ¢ alumina (see Fig. 9a). Another standard etchant for nickel, 92 HCl:5H,80,:3HNO4, revealed only the normal structure usually observed on nickel (Fig. 9b). The depth of grain-boundary modifications present in the Volatility Pilot Plant specimens was determined using the nitric-acetic acid etch- and-repolish technique described above. The maximum depth of these grain-boundary modifications for each corrosion specimen is recorded in Tables 10 and 11. The maximum amount of grain-boundary modifications was usually observed in the sections taken from the salt regions., For hnigh-purity nickel, the depth of the grain- boundary modifications was iound to increase in proportion to the distance from the top of the specimen (see Fig. 10). Bend Tests In order to gain preliminary information on how deleterious the grain- boundary modifications were on the properties of the fluorination specimens, a Tew bend tests were perlormed on the high-purity nickel samples. This material was selected because samples had shown grain-boundary modifica- tions with and without accompanying intergranular attack, Details of the test and the results are shown in Table 12. Fracturing occurred in specimens showing the modifications whether or not intergranular attack accompanied the modifications. However, the depth of the modifications did not seem to affect the depth of the 180-deg bend fractures. Summary The maximum total corrosion of the Volatility Pilot Plant specimens was determined in two ways: L. By summing the bulk metal losses, surface attack, and intergranu- lar attack. 2. By summing the bulk metal losses and the grain-boundary modifica- tions., Maximum values for each mode of attack were used in all cases. - 22 - UNCLASSIFIED Y-44748 - - ® " * ¥ 9 . - * - .‘ * & * . . LN .« '® . - . * . * . * ¥ > * . L s * v . - * . e - . . . . . s " ' . * . . * * . . - . . s .. - - . ¥u ¥ s * " - . 0‘* . » ’o - - ; - . ' * . - . * s * » 8 " . " ’ ot . (@) g » . " : - - » > - - .m . -» . * . . - UNCL ASSIFIED Y-44645 (5) Fig. 9. Development of Grain-Boundary Modifications in L Nickel 007 008 009 Q09 by Etching. Specimen 52B — vapor region. (a) Etched with 3CH;COOH:2HNO, and repolished. (b) Btched with 92HCL:5H,S0,:3HNC ;. Table 10. - 23 - Grain-Boundary Modifications in Group I Volatility Pilot Plant Fluorinator Test Specimens Grain- Boundary a Specimen Modifications No. Material Region (mils) 51 L nickel Vapor 1.5 conditioned Interface 9.5 Salt 11.5 51 INCO-61 Vapor 0 weld conditioned Interface 0 Salt 0 39 High-purity Vapor 12 nickel Interface 28 Salt 125 32 B nickel Vapor O 98 Ni—-2 Mn TInterrtace 2 Salt 3.5 24R 95 Ni—-5 Fe Vapor none Interface apparent Salt 27 90 Ni—-10 Fe Vapor O Interface & Salt 10 29 80 Ni-20 Fe Vapor 2 Interface 5 Salt 5 ol Except where noted, measurements transverse sections. are for b . R . Etching behavior may have masked grain- boundary modifications. C * s s g Measured in longitudinal section. Table 11. _ 24 - Grain-Boundary Modifications in Group IT Volatility Pilot Plant Fluorinator Test Specimens Grain- Boundary Specimen Modifications No. Material Region (mils) 52 L nickel Vapor 5.5 conditioned Interface 5.5 Salt 7 52 INCO-61 Vapor 0 weld conditioned Interface O Salt O 55 L nickel Vapor 6 not condi- Interface 4.5 tioned Salt 7 55 INCO-61 Vapor 0 weld not condi- Interface 0 tioned Salt O 17 95 Ni-5 Co Vapor 3.5 Interface 30 Salt 39 21 S0 Ni—10 Co Vapor 4 Interface 3.5 Salt 5 1R 99 Ni—1 Al Vapor none Interface apparent Salt 5 97 Ni—-3 Al Vapor 0 Interface 15.5 Salt 14.5 aMeasurements are for transverse sections., bEtching behavior may have masked grain-boundary modifications. UNCL ASSIFIED UNCL ASSIFIED Y-44749 Y-44750 . T——— .. _ TTT— - i N TN . o ¢ \-)((\ (‘\\ . S s s =z 3 . . . f 2 14 3. r i\ /y:;(,fi.«t Y * Lo woe - ' s k“\ N Lo e v . . 7 " . . i\ ~ -y . - e . . 0.02f ! ™ - » v - - ~ . 0.03] -~ . b . - 3 5 ' " [0 TOP VAPOR UNCLASSIFIED @ Y+44752 Ly S 3 S -— z ; . . | - ’ % 9.02 ‘1 L - \\, | it Voo a D b s 7 “ ) . \/‘j '.,/ . s . , { A 7 GO T f - i J z’“ >N 7 - P . T K »4 . Py A ”'; “ X Q]’ ‘ , T O s | L e N (T iy SN e L / ‘ ~ -~ ’ v . - [ | S« 7 - f -~ - 7 ; Y ! \ - A - P x i o : ‘L T z - ’ - INTERFACE SALT Fig. 10. Grain-Boundary Modifications in High-Purity Nickel Specimen 39, FEtched with 3CH3CO0H: 2HNO; and repoclished lightly on a microcloth wheel using O.1-u alumina. - D6 - Table 12. Grain-Boundary Modifications on Bend-Test Fracture of High-Purity Nickel Maximum Maximum Maximum Depth of Depth of Depth of Intergranular Grain-Boundary Fracturing After Attack Modifications 180~deg Bend Location (mils) (mils) (mils) Top O O Q Vapor 0 12 15 Salt 6.5 125 9 Bulk losses based on specimen radlii were used since aggressive attack on a process Tluorinator occurs essentially only on the inside diameter. Total corrosion ncted for the specimens is detailed in Tables 8 and 9. Corrosion rates for the fluorination specimens are shown in Figs. 11 and 12. The rates were determined on the basis of molten-salt residence time as well as fluorine exposure time. DISCUSSION OF RESULTS The individual effects of fluorine, UFg, and fluoride salts on container materials have been discussed previously.® The modes of attack observed in this current series were similar to those previously described. However, attempts were made to categerize better the corrosion modes. Comparison Between Group I and Group II Specimens The Group II corrosion specimens in general exhiblted higher corrosion rates than did the Group I specimens, probably due to the presence of uranium during the Group II rumns. Previous work has shown the accelerating effect uranium has on corrosion during fluorination.? Bulk metal losses, based on specimen radii, were about the same, 0.7 to 1.6 mils, for all the Group I specimens while the metal losses for the SA. P. Litman and A. E. Goldman, Corrosion Associated with Fluori- nation in the Oak Ridge National Laboratory Fluoride Volatility Process, ORNL-2832, pp 25-31 (dune 5, 1961). SPECIMEN NUMBER DESCRIPTION ] - | 'L'NICKEL | | F CONDITIONED | e | 51-WELD INCO 61 i METAL F CONDITIONED | e o 1 ] i " HIGH PURITY | L9 NICKEL L A | T ! E'NICKEL | i 32 98 Ni—2 Mn o *r . 24R | 95 N|—5Fe 27 ' 90 Ni-10Fe P ] 29 80 Ni—20 Fe | o e mil/mo BASED ON MOLTEN SALT RESIDENCE TIME UNCLASSIFIED ORNL—LR—DWG 70631 Fluorinator Test Specimens. 0 1.0 20 30 4.0 50 6.0 T T T } - . T T T T i B b 3 I | i i ; . | i ' 71 \ 1 N i 1 ‘ ! ' N — | | | | I i oy : 1 | | | . | | | S l O | o | o I | ‘ | ‘ | ! | | ! | | % i ; ; | i i ‘ 1 | i ‘ j : . | | ! | ; I 77T | 3 } ‘ i ; | : | : ; ! | | | | o ! | | | | | 3 | ! \ I | | | 1 ‘ ‘ . [ | | | | | - =% | | I I L 5 o | L | : ‘ ‘ —= 240 mil/mo ! | . | : ! - : | | | } ] | i ' : : i . ! ' i | , | | | . ‘ - | T | | | ? ; i LEGEND | . | | B 5u K METAL LOSSES ! | INTERGRANULAR ATTACK | ‘ ‘ ‘ EXEZ SURFACE ATTACK 1 i ‘ 3 ! 1 GRAIN BOUNDARY MODIFICATIONS i | : _ ‘ : \ 1 I | . — | | o T o | | 1 2R ! \ | ‘ ‘ E | | ! | | = o o . ] o o | | 1 f l % i : ‘ 0.5 10 15 2.0 2.5 mil/hr BASED ON FLUORINE TIME Fig. 11. Corrosion Rates for Group I Volatility Pilot Plant - LZ SPECIMEN NUMBER DESCRIPTION : 52 "L" NICKEL | F, CONDITIONED 1 s2-wELD | mCO &1 | METAL F, CONDITIONED | \ {77 - T . ss "L" NICKEL, NOT l L CONDITIONED | 55-WELD | INCO 61, NOT METAL CONDITIONED T ‘ 17 | 95Ni—5Ca o \ 21 ¢ 90 Ni-10 Co R IR 99 Ni—1 Al 5 97 Ni-3 Al Fluorinator Test Specimens. mil/mo BASED ON MOLTEN SALT RESIDENCE TIME UNCLASSIFIED ORNL-LR—DWG 70692 10 20 30 40 50 60 70 80 90 100 110 120 T 7 T T : A Lo ! ; | | i o | | i i I ! ' | ‘ | | | | ———_— P | ‘ \ P = \ | ‘ | ] . 5 ; | - T ! | b E ! \ | i | | ‘ | 124 mil/mo T T T T 3 v I T T T T T T [ T T ] [ T [ [ T [ | [ ! I 152 mit/mo | | | | | | ] \ i LEGEND & Il cuL< METAL LOSSES i INTERGRANULAR ATTACK ; f EEER SURFACE ATTACK ! [ GRAIN BOUNDARY MODIFICATIONS | ‘ I [ ) I N S O | f = TTTTIITTT]] LTI | 1.0 2.0 3.0 mil/hr BASED ON FLUORINE TIME Fig. 12. Corrosion Rates for Group II Volatility Pilot Plant - g2 - - 29 - Group II specimens varied from O to 8.6 mils. Group II interface sections usually exhibited the greatest bulk losses, while sections taken in the vapor region exhibited the least attack. Intergranular attack was most prominent in the L nickel and high- purity nickel specimens of Group I. The maximum depth of penetration by this mode of attack was 6.5 mils for the high-purity nickel specimen. In Group II, intergranular attack was found mainly in the L nickel and 95 Ni—5 Co specimens. For the unconditioned L nickel specimen, inter- granular attack to a depth of & mils was noted. Grain~boundary modifications were found in all specimens of Group I except INCO-6l weld metal and 95 Ni—5 Fe specimens. The L nickel and high- purity nickel specimens showed thne greatest amount of grain-boundary modifications — 11.5 and 125 mils, respectively. All the Group II specimens except the INCO-61 weld metal and the 99 Ni-1 Al specimens exhibited grain-boundary modifications. The maximum depth of attack by this mode of corrosion, 30 mils, was found in the 95 Ni—~5 Co specimen. Comparison With Previous Studies In general, the corrosion rates experienced by the Group I and Group IT specimens were about the same as those experienced by speclnmens in earlier tests.?’ Since many different alloys were tested 1n the current and previocus serics, the best comparison can be made by examining corrosion of the L nickel control specimens. Table 13 gives the maximum corrosion rates experienced by all such nickel specimens. As Table 13 indicates, during corrosion tests the L nickel specimens were exposed in NaF-ZrF, salts (usually with UF, present), while the Group I/Grouy IT tests were exposed to a LiF-NaF-ZrF, mixture. The addition of LiF lowered the salt melting point so that the fluorination could proceed at slightly lower temperatures. The lower operating temper- atures would normally decrease corrosion rates. However, as has been shown previously, the addition of lithium fluoride increases the corrosion rates on nickel” and the total effect was one of averaging so that compos- ite corrosion rates were about the same as in the early tests. Table 13. Comparison Between Maximum Corrosion Rates Experienced by L Nickel Specimens in Group I/Group IT Tests and in Corrosion Tests Maximum Corrosion Rate Based on Approximate Salt Based on Temperature Initial Bath Residence Fluorine Range Composition Time Time Tests Runs (°C) (mole %) (mils/month) (mils/hr) Corrosion M 21-M 48 505-700 50 NaF—50 ZrF, > 1007 > 4.0% teste C 9 15 500-650 48 NaF-—48 ZrF,—4 UF, 72 1.2 , E 3E 6 540—-660 48 NaF—49.5 ZrF,—2.5 UF, 45 0.8 3 L 1-L 4 560-710 54 NaF--4l1 7ZrF,—5 UF, T4 1.5 ! L 5L 9 540—700 52 NaF—45.5 ZrF,—2.5 UF, 27 0.7 Group I T 1-T 7 485-605 30 LiF-27 NaF—43 ZrF, llb O.5b Group IT U 1-TU 7 490575 29 LiF—29 NaF—42 ZrF, + 40 1.1 0.3 wt % UC aSpecimen was completely consumed. b Specimen was fluorine conditioned 3.2 hr at 600—645°C before test. All other speclmens were in unconditioned state. “Equivalent to 0.2 mole % U. - 31 - Effect of FPluorine Conditioning on L Nickel and INCO-61 Weld Metal In Group II, one of the L nickel-INCO 61 specimens was fluorine conditioned 3.2 hr at 600—645°C before corrosion testing. The conditioned L nickel appeared to have sustained somewhat less attack than unconditioned L nickel. On the other hand, conditioned INCO-61 weld metal exposed in the vapor and salt regions exhibited greater attack than did unconditioned INCO 6&1. These observations are compatible with the theory thatl corrosion resistance to fluorine is imparted by the formation oif a stable Iluoride Tilm. The increased corrosion resistance ol the conditioned L nickel presumably is due to the formation of a stable nickel Tluoride film. The titanium present in INCO 61 possibly modifies and makes the NiF, ilm less stable since titanium fluorides are highly volatile. CONCLUSIONS Several conclusions can be drawn based on the reported fluorination- corrosion tests. These conclusions are in agreement with the previous test series. 1. The combination of operating temperatures around 550°C with lithium fluoride present in the salt baths produces about the same bulk metal losses on nickel and nickel-base alloys as was found by operating at 650°C without lithium in the salt baths. 2. 'The presence of uranium accelerates corrosion of nickel and nickel-base alloys during the Volatility Process fluorination cycle. 3. Prior fluorine conditioning of L nickel decreases corrosion of the material during subsequent fluorination. 4. Prior fluorine conditioning of INCO-61 weld metal increases the attack on INCO 61 during subsequent Tluorination. 5. Bulk metal losses on L nickel and the nickel-binary alloys containing manganese, iron, cobalt, or aluminum are about the same during Tluorination at 550°C with lithium present in the fluoride salt baths. - 32 - 6. The presence of the alloying elements, manganese, iron, or aluminum, in nickel drastically reduces or eliminates intergranular attack usually Tound in unalloyed nickel exposed to a fluorination environment. 7. In fluorination environments, the effect of adding cobalt to nickel on subsequent corrosion by intergranular attack of trhe binary is unclear. These reported tests showed that serious intergranular attack of a 95 Ni—5 Co specimen occurred. On the other hand, this test series and previocus series showed good resistance to this form of corrosion by nickel containing 10 and 20 wt % Co. 8. Unalloyed nickel of greater than commercial purity shows less resistance to bulk metal losses, intergranular attack, and grain-boundary modifications when exposed to fluorination environments than L nickel and all nickel alloys tested. ACKNOWLEDGMENT The authors wish to acknowledge the assistance given by L. A. Amburn, Metallograpny Group, the X-Ray Difiraction Group, Metals and Ceramics Division, and by personnel of the Analytical Chemistry Division, Thanks are also due E. C. Moncrief, R. P. Milford, and others of the Chemical Technology Division who alded in gathering process data or in reviewing this report. Special thanks are due D. A. Douglas, Jr., R. 3. Crouse, and R. J. Gray for their constructive appraisal of this report, and to the Metals and Ceramlics Division Reports Office and Graphic Arts Department for preparation of the material for reproduction. APPENDIX Photomicrographs of metallographic sectlons taken from Groups I and II, nickel and nickel-base, corrosion specimens exposed in the Volatility Pilot Plant Mark ITI L nickel Tluorinator. - 34 - UNCL ASSIFIED Y-43351 { o) VAPOR UMCL ASSIFIED NICKEL PLATE ¥-43353 (c) INTERFACE UNCL ASSIFIED Y-43354 NICKEL PLATE . (e) SALT Fig. 13. Volatility Pilot Plant Fluorinator Test Specimens. right — as-etched with HNC3-CH3COOH-HCL. 007 NICKEL PLATE UNCLASSIFIED ¥-43352 001 - . L e 002 oy o _ r o Z 005 006 007 008! () VAPOR Gap e e o e g T 4SS CUNCLASSIEIED NICKEL PLATE-* i Y-44714 002 ( ’ ‘*Mwfigkflfiflwmemwfiwfidm%flwWf“* - w # o |z \ 008 006 oo7T oos| {7} INTERFACE S . UNCL ASSIFIED oot | ANICKEL PLATE . Y-44715 o] o B , P 4 i3 008 ey (F) SALT Sections from L Nickel Specimen 51 from Group I, Left — as-polished; 300%. - 35 - UNCL ASSIFIED Y-43357 | 008 £07 {g) VAPOR UNCLASSIFIED Y-43355 (£) INTERFACE NICKEL PLATE UNCLASSIFIED Y“43356 L00i UFY eran L SEMIMETALLIC g P T P ; 2 iy L M T e e i o INCO ©f ‘ 007 {c) SALT Fig. l4. Sections from INCO-61 Weld Deposit of Specimen 51 from Group I Volatility Pilot Plant Fluorinator Test Specimens. As-polished. 300X. UNCL ASSIFIED Y-43375 0086 07 {g) VAPOR UNCLASSIFIED Y-4335% R |00t () INTERFACE ] B UNCLASSIFIED _Y-43358 (¢) SALT Fig. 15. Bections from High-Purity Nickel Specimen 39 from Group I Volatility Pilot Plant Fluorinator Test Specimens. As-polished. 300X. - 37 - UNCL ASSIFIED Y-43376 (g) VAPOR ! - » . * . UNCLASSIFIED [ , : +NICKEL PLATE . ¥-39320 ‘ | - :‘ “f' ‘ : 220 < - |.o08 Lt0 . 011 01s . -~ NICKEL PLATE o ¥-39319 o - W (c) SALT Fig., 16. Sections from 98 Ni—2 Mn Specimen 32 from Group I Volatility Pilot Plant Fluorinator Test Specimens. (a) As-polished. 300X. (b) As-etched with HNO;-CH;COOH-HC1l. 250X. (c) As-etched with HNO,-CH,COOH-HCL. 250X. . 38 - L UNCL ASSIFIED Y-43363 L0 .006 007 UNCL ASSIFIED NICKEL PLATE L ASSI A T Py s I T It (g} VAPOR 008 (p) VAPOR UNCL ASSIFIED Y+43364 UNCLASSIFIED NICKEL PLATE L ASSIF (¢) INTERFACE UNCLASSIFIED Y-43373 (e) SALT 006 e UNCLASSIFIED Y-44718 NICKEL PLATE wn | ¢ 5 / |z \\ S, N / Loos| N f}/ ol L[ - ~ . oos| (F) SALT / - Fig. 17. Volatility Pilot Plant Fluorinator Test Specimens, right — as-etched with HNO3-CH,COOH-HCL. Sections from 95 Ni—5 Fe Specimen 24R from Group I Left — as-polished; 300%. - 39 - UNCL ASSIFIED Y-43365 {g) VAPOR UNCL ASSIFIED Y-43346 {¢) INTERFACE BB UNCL ASSIFIED (e} SALT Flg. 18, Volatility Pilot Plant Fluorinator Test Specimens, right — as-etched with HNO3-CH3COOH-HCL. Y-43367 | D07 .008 e UNCLASSIFIED NICKEL PLATE Y-44719 008 () VAPOR UNCL ASSIFIED NICKEL PLATE Y-44720 LR Mgt age o i | .002. w LD x [ &) z G008 008 007 008! () INTERFACE UNCLASSIFIED (F} SALT Sections from 90 Ni—10 Fe Specimen 27 from Group I Left — as~polished; 300%. {a) VAPOR (¢} INTERFACE {e) SALT Fig. 19. . UNCLASSIFIED NICKEL PLATE N UNCLASSIFIED Y.43370 ooz} " LN " T oY “C‘ v -~ LI T om(6) VAPOR (¥ 3 F et SR T AR UNCL ASSIFIED » NICKEL. PLATE Y y.44721 Q08 — UNCLASSIFIED Y-43369 .006 D07 17 Y (o) INTERFACE - Qo8 rmm— Sections from 80 Ni—20 NICKEL PLATE (£} SALT Fe Specimen 29 from Group I Volatility Pilot Plant Fluorinator Test Specimens. Left — as-polished; right — as-etched with HNO3-CHsCOOH-HCL. 300X, - 4] - B UNCL ASSIFIED Y-44644 {g) VAPOR B UNCL ASSIFIED Y~44646 B (&) INTERFACE UNCL ASSIFIED Y-44648 (¢) SALT Fig. 20. BSections from L Nickel Specimen 52 from Group II Volatility Pilot Plant Fluorinator Test Specimens., As-polished. 300X. 008 O0T .008 008 007 .co8 008 - 4D - UMCIL.ASSIFIED Y.44645 & {g} VAPOR UNCLASSIFIED Y.44647 ; v — {p} INTERFACE {ED {c) SALT Fig., 21. Sections from L Nickel Specimen 52 from Group II £09 007 008 008 Volatility Pilot Plant Test Specimens. As-etched with 92HCLl:5H,804: 3HNO;. 300X, UNCLASSIFIED Y-44651 i % /‘ e fi\\ # - e - - : ’ ’ s ; }' (\:? W n’:fi "t : w ‘»(‘ : M Cd . (g) VAPOR N T e S EEE AN 125?“ P AR Uy B TR s T e R -, f L - o * & Loy oA 1* E‘ UNCL ASSIFIED Bl S ead R NICKEL PLATE U “ B o T AR Ty 44653 - L o e 5. ST— e g g e e, gt R g WW% L e {p) INTERFACE & (¢) SALT Fig. 22. Volatility Pilot Plant Fluorinator Test Specimens. 300X. 92HC1: 5H50,: 3HNOS. *@ % UNCLASSIFIED CLE Y-44656 Sections from L Nickel Specimen 55 from Group IT As-etched with 007 .006 Q0T .008 .006 007 008 IR UncUASSIFIED L d v.44641 (@) VAPOR 010 UNCL ASSIFIED _ Y-44642 007 009 (H) INTERFACE UNCLASSIFIED Y-44643 07 008 £08 (¢) SALT Fig. 23, Sections from INCO-61 Weld Deposits of Specimen 52 from Group II Volatility Pilot Plant Fluorinator Test Specimens. As-polished. 300¥. - 45 - [ UNCLASSIFIED Y- 44660 o (=] ra INCHES ¥ L o < 003 0086 (g} VAPOR i : 008 UNCL ASSIFIED Y-44662 oo v " e Lo 009 UNCLASSIFIED Y-445665 0035 009 Fig. 24. Sections from 95 Ni—-5 Co Specimen 17 from Group IT Volatility Pilot Plant Fluorinator Test Specimens. As-etched with 92HC1:5H,50,: 3HNO,. 300X, - 4 - UNCLASSIFIED Y-44666 (g} VAPOR UNCLASSIFIED Y-44669 (6) INTERFACE UNCL ASSIFIED Y-44671 (¢) SALT Fig. 25. Sections from 90 Ni—10 Co Specimen 21 from Croup IT Volatility Pilot Plant Fluorinator Test Specimens. Vapor section is as-polished. Interface and salt sections are as-etched with 92HCL: 5H,80,: 3HNO,. 300X. .006 007 008 " L09 .008 007 008 009 006 .007 08 man - 47 - UNCLASSIFIED Y.44673 (@) VAPOR UNCLASSIFIED Y-44675 (b) INTERFACE UNCL ASSIFIED Y-444677 (¢} SALT Mg, 26. 8ections from 99 Ni—1 Al Specimen 1R from Group II Volatility Pilot Plant Fluorinagtor Test Specimens. As-etched with 92HCL: 5325@4: 3HNO3 . 300X, 008 007 008 fl—cey 008 gor .00B Kok 006 L0a7r L8048 pr— 009 hod el - 48 - UNCIL_ASSIFIED (o) VAPOR UNCL ASSIFIED Y-44682 ——— (p) INTERFACE 1 o UNCLASSIFIED Y.44634 (¢) SALT Fig. 27. Sections from 97 Ni-3 Al Specimen 5 from Group IT Volatility Pilot Plant Fluorinator Test Specimens. As-etched with 92HCL: 5H80,: 3HNO,. 300X. .006 007 008 0086 007 £08 008 L0t L08 2=3. o220, 21. 22. 23. 24—25. 26. 27. 28. 29, 30. 31. 32. 33. 34. 35. 36. 37. 38, 39. 40, 41, 43, 4bdi5, 47, 48. 49-51., - 49 - DISTRIBUTION Riology Library 52. Central Research Library 53. Reactor Divigion Library 5456, ORNL — Y-1l2 Technical Library 57. Document Reference Section 59, Laboratory Records Department 59 Laboratory Records, ORNL R. C. 60. ORNL Patent Office 6. G. M. Adamson, dJr. 62 R. E. Blanco 63 J. C. Bresee 62, B. 5. Borie 65 R. B. Briggs 66. K. B. Brown 67 W, H. Carr 68. G. I. Cathers 69. R. 8. Crouse 70, F. L. Culler 71 J. E. Cunningham 75_86 | J. H. DeVan D. A. Douglas, Jr. 87. D. E. Ferguson J. H Frye, Jr. 8. H. E. Goeller 89, C. E. Guthrie 90. R. J. Gray 91 . W. R. Grimes 90, R. W. Horton 93, M. R. Hill FE. E. Hoffman H. Tnouye T. M. Kegley, Jr. Lamb Lindauer Litman Long, Jr. MacPherson Manly McHargue Milford . Miller Moncrief Olsen = 0 Q "oy g Q@ oot . Patriarca B. Ruch H. Smiley 0. Smith Taboada C. Thurber E. Whatley S P 0P LT rEBE®QEEE D = Divigion of Technical Information Extension (DTIE) Research and Development Division (ORO) E. L. Anderson, AEC Washington 0. E. Dwyer, BNL 5. Lawroski, ANL P. D. Miller, BMI J. W. Nehls, ORO C. M. Slanksky Phillips Petroleum Company, Idaho Falls