n}{ 3f!' ..... ttC I 

NRO APPROVED FOR RELEASE 

DECLASSIFIED BY: C/IART i 

DECLASSIFIED ON: 25 JULY 2012 

WORKING P,~PER. DESTROY 

OR CONTROL BY d~~ , 

OPTICAL TECHNOLOGY DIVISION 

OPTO-MECHANICAL DESIGN ENGINEERING 

Memorandum ME 50 

TO: Project File - Recovery of RV #3 ~ DATE: August 5, 1971 

FROM: L.B. Molaskey 

SUBJECT: Effect of Salt Water on Beryllium 

At the meeting of 30 July 1971 held at MWC concerning the recovery 

of RV #3, a question of the survivability of the beryllium when immersed in 

salt water was brought up. Investigation into the matter has produced evide.nce 

that although there is certain to be corrosion on the beryllium, it is very 

doubtful that serious damage to the structural integrity of the, core and/or 

shaft components will occur as a result of corrosion. The attached data indicates that even when cycled through salt water immersion and elevated tempera" 

tures in air, the effects of corrosion are insignificant compared to the structural function of the take-up core and shaft. 

It is therefore concluded that corrosion of the beryllium components 

will be negligible compared to the other effects of'water impact and subsequent 

immersion in sea water. 

LBM/cj 

cc': MoF 0 Maguire 

HoW. Robertson 

R.W. Jones w/enc 

C. Karatzas 

) w/enc 

(MWC) w/enc ~cl~ot:581er (EK) w/enc 

L 0yMolaskey 

'!'fO,.';·: :'~ : ..... ~:t~, DESTROY 

CI~· CL- 1'; -:" ;{CL ;j ·,or C:~\) 
( 

I 

It is pointed out, however, t •• dt corrosion 

rates in such service are higher than can be 

tolerated,so that addiliollal protcction is required for satisfactory service life. 

Salt Fog 

" Bare beryllium specimens (nominal 2 

percent BeO content) were exposed to a S percent salt-fog spray at 100 F for 30 days at thc 

Astropowcr Laboratory. (7) Localized pitting 

occurred on thc bare pieces after only 1 day of 

exposure. The attack increased with exposure 

time. Th~ specimens were rinsed in distilled 

water after 30 days and then were wcighed. The 

'weight loss at several time intervals is given hi 

Table 4. The values in the last column (actual) 

were .obtained by dissolving the corrosion product 

in 49 percent HN03 and 1 percent HF and adjusting for the bare metal dissolved. The cor-

, rosion rate corresponding to weight losses in 

the range shown is Z. Z mpy. Pit depths of IS 

to 25 mils were measured on the coupons. 

TA8LE 4. WEICHT LOSSES OF FORGED IxZ-IN. IN 5 PERCENT 

SALT-FOO SPRAY AT 100 F . (ReI.unce 7) 

, "elaht Lo .. at 

indicated Exposure Times, mg 

l 4 7 14 21 30 )0 

Specimen Day Dar" Day. Days Oars Day. Days Days (Actuall'a) 

'-4 O. 33 O. 50 O. 90 I. 6 

5·4 O. 4Z O. 7 O. 89 I. Z 

5-5 0.40 0.7 0.91 I. I 

I-I O. 5 O. 71 O. 9 

3.8 5.6 

Z.3 Z.7 

Z.O Z.4 

1.9 2.6 

7.3 23. I 

3.1 27.Z 

Z. 9 17.6 

l.5 ZZ.5 

(a) (Actual) values indicate weight lones of IpeC:imenl after 

. corrosion p~oduc:ts were stripped from coupon .. and are 

equivalent to about Z. 2 mpy. 

In another study at the same laboratory, 

coupons were alternately exposed to a 5 percent 

salt fog at 100 F for 16 hours, and then immediately placed in an oven for 8 hours at ZOO, 400, 

600, or 800 F. . 

The following observations were reported 

tor polished beryllium when exposed to alternate 

cycles of salt-fog spray and elevated temperature,. . 

(1) Chemical attack was observed on polished bare beryllium following the initial 

cycle at all of the above temperatures. 

(Z) At ZOO F the pitting ~bserved after the 

lirat initial cycle increased with each 

subsequent cycle as evidenced by the 

increase in the number and size of the 

pits. The behavior at this condition is 

very similar to the results obtained for 

the 30-day, 5 percent salt-fog spray. 

~ ". 

(3) At 400, 600, and 800 F, the cyclic 

e£tect of temperature and salt 

contaminatiun was found to proceed 

. by two independent mechanisms. 

5 

Acids 

Initiall/ weight loss was observed, 

due to chemical attack by tho salt 

environment. After the first few 

cycles, a thin oxide coating was formed,duf: to oxidation in air at the elevated temperature. 

(4) At 800 F, very small white oxide 

patches started to appear at about 

about the tenth cycle. At this stage 

the coupons started to show small 

weight i~creases~ The appearance 

oJ the white oxide is indicative of the 

onset of the catastrophic oxidation, 

which is. discussed later in this report. 

.. 

Beryllium reacts. with the halogen acids·in 

all concentrations at room temperature. It reacts 

with dilute sulfuric acid readily and with concentrated sulfuric acid slowly. It is attacked by 

dilute nitric and acetic. acids, but not glacial acetic 

acid or concentrated nitric acid at room temperature. With concentrated nitric acid, reaction 

occurs and becomes violent as the temperature is 

increased above room temperature. 

Straumanis and Mathis report studies with 

premium-grade vacuum-cast metal (assaying 

99 •. 0 percent Be) in HF, HC1, and HZS04. (12) 

The metal is removed uniformly in HF and HiS04. 

The' reaction with IfCl is more localized, and a 

black deposit forms which has been identitied as 

£ine needles of metallic beryllium. The black deposit was not found when concentrations greater 

than O. 5N HCI were used. 

The reaction mechanisms were checked by 

measuring the volume of hydrogen evolved from 

weight samples. It was concluded that thereactions with acids are: 

~e + ZHF - BeFz + HZ 

Be + ZHCl - BeClz + HZ 

Be + H2S04 - BeS04 + Hz. 

Rapid attack and the formation of a black 

deposit were observed in HCI04 and HBr. 

It is interesting that a similar black deposit, 

consisting mainly of fine beryllium needles,is 

formed on beryllium anodes when the.metal is 

electrolytically disolved in a 0.5N HClsolution. (13) 

Alkalies 

Beryllium is vigorously attacked by aqueous 

alkaline solutions. Molten alkalies may react 

. explosively with the metal. 

NRO APPROVED FOR RELEASE 

DECLASSIFIED BY: C/IART 

DECLASSIFIED ON: 25 JULY 2012 
4 

'tABLE 2. CORROSION OF BER( LIUM IN SALT 35----.;.,.....-i 1.05 

SOLUTIONS AT 60' F (Reference 9) 

Overall 

Corrosion 

Rate(a) I Max Pit Depti:ll 

Environment mpy mils 

Distilled water 0.8 o. S(b) 

Synthetic seawater 13.7 4.6 

Natural seawater 18.4 4.6 

3% NaCI solution 21.5 

3.5 NaCI solution 33.4 6.8(c) 

30 

-. 

~ 25 ..... 

CJt 

E 20 

,; 

on 

o 

..J 

.c 

-

CJI 

; 5 

0.9 .!! 

0 0 0 'E 

() ·0.75 

.§ 0 0.6 0 

.. 

1; 

0.45~ 

0.3 .. 

CI 

.e 

0.15 ~ 

20 40 GO 80 100 120 140 160 

Ca) Tiine. days 30 days. 

(b) IS days. 

(c) 8 days. . ... :. FIGURE 3. CORROSION OF UNSTRESSED, 

PICKLED BERYLLIUM SHEET MATERIAL EXPOSED TO SYNTHETIC SEAWATER 

TABLE 3. CORROSION IN NATURAL SEAWATER 

AT ABOUT 60 F 

Continuous ~otal immersion. (Reference 9) 

Corrosion Max Pit 

~Timel rate l Depthl Percent oC SurCace 

days' mpy mils Pitted 

2 1.5 Negligible 

5 1.6 1 

. 20 13.0 3.0 5 

30 10.5 3.0 12 

40 9.0 Z.S IS 

60 6.5 3.0 20 

182(a) 2.4· 

(a) Extrapolated value. 

It should be pointed out that the maximum 

pit depth also increased in a similar manner 

from about 1. 6 to 3. Z mils as the exposure time 

increased from 5 to. 150 days. A summary oC 

the results concerning pitting is given in Figure 

4. It can be noted that the percentage of the surfaces pitted increased linearly from about Z to 

45 percent as .the exposure period increased 

. from 5 to 150 days. 

In work at Battelle, a. yerx low &encral!.!!.e 

0!.!lla,<;~_ w~~. fOY-.nd for beryllium ill seawater I 

but evidence of possible pitting was also observed. 

The'beryllium was exposed in aerated seawater 

(except for a period o£ about 6 hours a daYI for 5 

days a weekI when it was suspended above the 

water). After Z weeks I exposure, the corrosion 

rate was equivalent to 3. 6 mpy. The surface 

appeared to be coated with a while powder. probably BeO, and had small-size clear hydro scopic 

bubbles on its surface. Underneath these bubbles 

some pitting was Cound. 

.... 

4.0 

3.2 

2.8 

. 

-; 2.0 0. 

.. 

o 1.6 

a:: - 1.2 

0.8 

0.4 

AT 77 F 

(Continuous total immersion testing. 

Reference 11). 

, ..... 

- V !-- Max. pit depth 0 

- [;?; 0 0 

f-7 ~ 

. 

FJ·c ~ e Avg. pit depth V 0 

0 0 0 

I!"o, '/ ~ 

f- 11 

~ 

'1:) 

.. 50:: 

a:: 

40 ~ 

o 

30 -~ 

(J) 

20 '0 

I -c 

o ~ ... 

II) 

l,{.:cent of SurfOr 

~ pitIed I I 

o a. 

20 40 60 80 100 120 140 160 

Exposure Time, days 

FIGURE 4. PITTL'lO ATTACK OF UNSTRESSED, 

PICKLED BERYLLIUM SHEET MATERIAL EXPOSED TO SYNTHETIC SEAWATER 

'AT 77 F 

Continuous total immersion testing • 

(Reference 11). 

Workers at Astropower exposed bare beryllium (nominal 2 percent BeO content) specimens 

alternately to a 5 percent salt solution at 100 F for 

16 hours,Collowed by air exposure at elevated temperatures up to 800 F Cor 8 hours. (7) Tests were 

continued Cor a total oC 14 c:ycles. The specimens 

were first attacked at localized areas (pitting). 

The maximum corrosion resistance was found at 

600 F and was attributed to the formation of a 

protective oxide film. 

NRO APPROVED FOR RELEASE 

DECLASSIFIED BY: CIIART 

DECLASSIFIED ON: 25 JULY 2012 
", 

e. 0 o 

u 

(I) 

c 

CP 

0> 

e 

"0 

:t -I ...... 

., 

'0 -

> 

r------r-----~( 

Corrosion Pas-sivation Corrosion 

8e++ 

".---~- . 

o 

:;: 

c -2 F-----"""-~ 1!. 

~ 

-3 

o 

Imml,!nlty 

Be 

pH 

nOURE 1. EQUILIBRIUM POTENTIAL - pH 

FOR THE SYSTEM BERYLLIUMWATER AT 77 F(6) 

14 

Alloy additions of nickel or co~binations 

of nickel and iron (4000 ppm Ni. ZOOO ppm Ni2000 ppm Fe. or 5000 ppm Ni-5000 ppm Fe) 

greatly improved the corrosion resistance of 

high-purity ber)·llium. For example. specimens 

made from alloyed Pechiney CR-grade powder 

showed no signs of attack for times up to 43 days 

In water at 650 F. The beneficial effect from 

nickel was not conCirmed by Stonehouse and 

associates. (Z) 

. Additional research will be required to 

clarify the cause of the unpredictable behavior 

oC beryllium. There is some indication that it 

is related to the presence of small amounts of 

copper contamination in the water. General 

results can be sun',marized as follows: 

(1) Specimens with acid etched sur£aces 

were less corrosion resistant than 

those not etched. 

(2) Mechanical removal of more than'12-14 

mils of the outer surface also rendered 

the specimens less corrosion resistant. 

(3) Localized boiling on specimen surfaces 

increased the corTosion rate. 

3 

Beryllium s( :mens exposed to stearn at 

752 F at 1500 psi \i.·ere attacked in much the same 

mannel' as those in water at 650 F: The localized 

attack in steam was somewhat more severe. 

Salt 'Solutions 

As was mentioned in an 6arlier section. 

beryllium is subject to pitting attack in aqueous 

environments cOlltaining chloride ion. Intermittent immersion tests conducted by Prochko 

and associates(9.IO) at ambient temperatures 

(about 60 F) and 30 'days of exposure indicated 

overall corrosion rates and penetrations listed 

in Table 2. Corrosion-test specimens were prepared from cross-rolled, surface-ground, fiashpickled (HF-HN03) sh·eet. The 60-mil beryllium 

. __ sheet of. comZ?.crcialpurity assayed 98. 3.per.£~nt ... ____ _ 

Be" 1.63 percent BeO, and O. 113 percent carbon. 

Figure Z shows the weight losses and penetrations for the specimens in the five test solutions after intermittent exposures. 

0 Distilled Woter lit 

50 1.5 

.!: A 3% NoCI E 

D' 40 0 3.5% Noel C 

.:!! D Syn the tic seoYloter 1.2 .2 01 

E 

0 NOhirol seoViote - 30 0 

... .; -I) 

." C 

0 20 0.6 CP 

-' Q. 

- G) 

.r. 0> 

0> 0.3 CI 

ti ... ~ 

., 

:> 

« 

10 20 30 

Time. doys 

FIGURE Z. CORROSION OF PICKLED BERYLLIUM SHEET IN FIVE ENVIRONMENTS 

(Intermittent total immersion testing. 

was conducted using these selected chloride solutions at 60 F. '(Reference 9) 

Exposures at 60 F and 9S F showed that 

the corrosion rate increased as the temperature 

was raised. For example. after 14 days of intermittent total immersion in natural seawater the 

rates for the above temperature s were 17. I and 

25. 9 .mpy. respectively. By compariso,\ the 

corrosion rate for anodized beryllium was only 

O. 3 mpy after 60 days in seawater. 

The corrosion rates decreased with time 

'oC exposure for samples exposed continuously at 

60 F in natura'! se.awater. Results are summarized in Table 3. 

A later report from the same laboratory 

indicates that the corrosion rate of beryllium in' 

synthetic seawater decreases (rom about 21. Z mpy 

at 5 daiS' exposure to about 3.0 mpyat 150 

days. ( I) Figure 3 illustrates these results. 

NRO AP~ROVED FOR RELEASE 

DECLASSIFIED BY: CIIART 

PECLASSIFIED ON: 25 JULY 2012