Publisher’s version / Version de l'éditeur:
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la
première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
Internal Report (National Research Council of Canada. Division of Building
Research), 1967-01-01
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.
https://nrc-publications.canada.ca/eng/copyright
NRC Publications Archive Record / Notice des Archives des publications du CNRC :
https://nrc-publications.canada.ca/eng/view/object/?id=ac89b42b-8ac0-4e4a-9454-8f4f836cb7f7 https://publications-cnrc.canada.ca/fra/voir/objet/?id=ac89b42b-8ac0-4e4a-9454-8f4f836cb7f7
For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.
https://doi.org/10.4224/20337842
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Corrosion behaviour of sheet copper and muntz metal in eight
Canadian atmospheres: a five-year progress report
NATIONAL RESEARCH COUNCIL CANADA
DIVISION OF BUILDING RESEARCH
THE CORROSION BEHAVIOUR OF SHEET COPPER AND MUNTZ MET AL IN EIGHT CANADIAN
ATMOSPHERES -- A FIVE-YEAR PROGRESS REPORT by
E. W. Beggs
Anaconda American Brass Limited, New Toronto, Ontario
and
ANALYIED
E. V. Gibbons
Di vision of Building Re search,
National Research Council, Ottawa, Ontario
A Joint Report of the Anaconda American Brass Limited and the Division of Building Research, National Research Council
Internal Report No. 338 of the
Division of Building Research
OTTAWA January 1967
An outdoor metals exposure program was undertaken by the former Associate Committee on Corrosion Research and Prevention (A. C. C. R. P. ) of the National Research Council to fulfil the need for more published information on the corrosion behaviour of various architectural metals in different locations in Canada. This cooperative study involved metal supplier s , user s and research or ganizations. The first metals were selected for exposure during 1953
and set out at the eight outdoors sites operated by the Division. The initial group of metals exposed included three types of steel, three stainless steels, two magnesium alloys, a rolled zinc, three aluminum alloys and rivetted galvanic couples of aluminum 35 alloy coupled to zinc, copper and mild steel. Reports have been issued describing the 10-year behaviour of these metals at the different sites. Other metals have been set in the years following the start of the program. This report describes the 5-year performance of specimens of sheet copper and muntz metal.
The specimens of copper and muntz metal were furnished by Anaconda American Brass Limited, New Toronto, Ontario. They were re sponsible for as se s sing their perfor-mance and assisting in the compilation of this report. This part of the study was under the direction of Mr. E. W. Beggs. The arrangements for exposure and examination of specimens and some over-all co-ordination of the program were carried out under the direction of Mr. E. V. Gibbons of the Division of Building Resear ch,
The Division is indebted not only to the companies who have cooperated in making this study possible, but also to those who have contributed to the provision and servicing of certain exposure sites.
Ottawa
January 1967
N. B. Hutcheon Assistant Director
THE CORROSION BEHAVIOUR OF SHEET COPPER AND MUNTZ METAL IN EIGHT CANADIAN
ATMOSPHERES -- A FIVE-YEAR PROGRESS REPORT by
E. W. Beggs
Anaconda American Brass Limited, New Toronto, Ontario
and E. V. Gibbons
Division of Building Research,
National Research Council, Ottawa, Ontario
A program to determine the relative corrosion behaviour of different architectural metals, when exposed at different locations acros s Canada, was undertaken by the former Associate Committee on Corrosion Research and Prevention of the National Research Counc Il , The metals selected by the Committee were set out at the outdoor sites of the Division of Building Research in 1953. Since this time the over-all program has included exposing at different times, specimens of three aluminium alloys and rivetted galvanic couples of 3S aluminium alloy to zinc, copper and mild steel, three low alloy steels, three stainless steels, rolled zinc, two lead alloys, two magnesium alloys, monel and a number of different metal and organic coatings on steel. This report describes the five-year performance of the sheet copper and muntz metal, furnished by the Anaconda American Brass Limited and set out in 1959.
The specimens exposed were flat sheets, 4 by
6
in. in size. They were held in place by porcelain insulators at 30 deg to the horizontal, facing south. Twelve specimens of each type of metal were set out initially at each site. This enabled three specimens of each to be removed after exposure periods of one, two, five and ten years of exposure. After the specimens were prepared, by the supplier, they were cor ner notched for orientation, identified by a drilled hole system and weighed prior to shipment to the sites. After each exposure period the appropriate lot was removed and returned to D.B. R. for checking and photographing. The lot was then forwarded to Anaconda for cleaning, re-weighing and corrosion evaluation.DESCRIPTION OF MATERIALS
The copper sheet used was taken from the regular run of ORC brand
*
electrolytic tough pitch copper. The specimens for exposure were 4 by 6 by 0.039 in. in size. The chemical composition of this grade of copper sheet was reported to be as follows:Copper, per cent Nickel Iron Arsenic Antimony Lead Selenium Tellurium Bismuth Sulphur Oxygen
Silver, oz. per ton Gold, oz. per ton
99.96+ 0.0005 0.0006 0.0005 0.0001 0.0002 0.00003 0.00004
<
0.00005 0.0008 0.03 0.30 0.003The muntz metal specimens were 4 by 6 by O. 042 in. in size. They were made from rolled, flat stock that is commonly used in architectural work as panels. The chemical composition of the stock used for making the exposure panels was reported to be as follows:
Copper, pe r cent Zinc Lead Tin Iron Manganese Silicon
DESCRIPTION OF TEST SITES
61. 50 38.41 (by difference) 0.005 O. 01 0.01 0.02 0.05
The sites were provided with tubular racks and stainless steel frames for mounting the specimens. A complete des cription of the atmospheric test sites us ed has been published (1).
3
-Site No.1, Ottawa - This site is located on the easterly city limits and can be classified as semi-rural.
Site No.2, Saskatoon - This is a rural site located on the campus of the University of Saskatchewan on the outskirts of Saskatoon.
Site No.3, Montreal - This is an industrial site located on the roof of a CNR Stores building in the Point St. Charles District.
Site No.4, Halifax - This is a marine -industrial site located on the roof of a Feder al Public building in the downtown area, two city blocks from the harbour.
Site No.5, York Redoubt - This is a rural-marine site, located approximately seven miles from Halifax. It is at an elevation of about 100 ft and 300 ft from the ocean. Site No.6, Norman Wells - This is a far northern site located in the Mackenzie River Valley approximately 90 miles south of the Arctic Circle.
Site No.7, Esquimalt, B. C. - This is a rural-marine site located at the southeast extremity of Vancouver Island, 15 miles from the City of Victoria. It is at an elevation of 50 ft and approximately 1500 ft from the ocean.
Site No.8, Trail, B. C. - This is a semi-rural site located at Birchbank in the Columbia River Valley six miles north of the City of Trail.
In addition to meteorological data being available from weather stations of the Department of Transport near the sites, the sulphur dioxide content of the atmosphere was determined, using the lead peroxide method. This method does not measure the volumetric concentration of S02 in the atmosphere directly but presents an integrated measure of the sulphur dioxide "'act.ivi.ty!' during a period of exposure. It was found that this instrument was well suited to measure the relative levels of S02 at the
exposure sites when metals are under test. The measure-ments were made on a monthly basis at each site. The results have been condensed and the average levels during the five-year exposure of the copper and muntz metal are given in Table I. Figure 1 is a graphical representation of the average concentration of sulphur dioxide at each test site.
EXAMINATION PROCEDURE
The amount of corrosion of the electrolytic copper sheet C- 6 and the muntz metal C-7 specimens was determined by the loss in weight of the panels after employing a standar-dized cle aning procedure. The panels were examined
visually to obtain an indication of any deposition of foreign material, corrosion products and discoloration. Differences in appearance after cleaning were noted between the under-side and topunder-side. Observations for pitting were also made on the cleaned specimens.
Cleaning of the exposed sp ec irne
ns
consisted of dipping them in 10 per cent sulphuric acid for 10 to 15 sec at room temperature, scrubbing by hand with a bristle brush, rinsing in cold and then hot water and finally dipping in alcohol to dry. An unexposed specimen was cleaned by the same procedure to determine los s of metal due to the cleaning operation and to obtain a corrected weight. OBSER VA TIONSThe most noticeable difference in appearance with exposure was the disappearance of the bright metallic shine of the specimens and the development of the brown copper oxide coating in both materials. This was true of the top-sides and undertop-sides. Exceptions to this were at the Norman Wells and Saskatoon sites where the brassy appearance of the muntz metal was still in evidence on a large portion of the topside after 1 and 2 years' exposure and after five years in these atmospheres on the underside. A heavy patina had developed on the copper panels exposed at the Halifax site by the end of five years. The brass appearance of the muntz metal by this time had completely disappeared, and the specimens looked somewhat similar to those made from copper sheet.
The weight losses and the corrosion rates of the copper and muntz metal specimens exposed at the different sites are given in Tables I I and I II, respectively. From these tables and Figures 2 and 3 it is seen that the Halifax site (site No.4) has provided the severest exposure condition by far. The sulphur dioxide content of its atmosphere (Figure 1) is much higher here than at any other site and this no doubt
5
-accounts for much of the corrosiveness. The copper sheet withstood this particular environment considerably better than the muntz metal. The weight loss of the latter metal is almost twice that of the copper after five years of exposure. The next most corrosive sites in order, with respect to muntz metal, are Montreal and Halifax. This order is reversed with the copper specimens. Also in Figure 1 it is of interest to note that the S02 level of the Montreal site is about double the values recorded for Trail.
The corrosion rates of the copper and muntz metal specimens for different periods of exposure are shown graphically in Figures 4 and 5, respectively. It is observed that with the exception of Trail, for the first year of exposure, the corrosion rate for copper decreases with years of exposure.
In general, the corrosion rates for the muntz metal remains fairly constant throughout the five years of exposure. This would indicate that little protection results from the corrosion products formed. An exception to this constant rate of corrosion is shown with lot 3 specimens at the Halifax roof site. Although a constant rate prevailed for the first two years there was a drop in rate at the end of five years (Table III). This change may have been due to
the accumulation of soot that prevented removal of the corrosion products as they were formed.
There was little or no evidence that pitting had occurred to either metal at any of the sites. Both materials presented a smooth surface after cleaning and examination under low power magnification.
CONCLUSIONS
1. The corrosion rate of the copper sheet decreases with time. 2. The muntz metal is more sus ceptib1e than copper to
attack from atmospheric sulphur dioxide.
3. The corrosion rate for the muntz metal has remained fairly cons tant, with a few exceptions throughout the period of exposure.
4. Pitting has not been a serious proble m with either metal at any of the exposure sites.
REFERENCES
1. Gibbons, E. V. Outdoor Exposure Sites of the National Research Council. Chemistry in Canada, Vol. 12, No.3, March 1960, p.44-48. (NRC 5593)
7
-TABLE I
Average Amount of Sulphur Dioxide in the Atmosphere at Each Test Site from 1959 - 1964
2 Site No. Location Mg S03/dm /day
1 Ottawa 0.53 2 Saskatoon 0.12 3 Montreal 1.37 4 Halifax 3.34 5 York Redoubt 0.22 6 Norman Wells 0.007 7 Esquimalt 0.06 8 Trail 0.64
TABLE II
Weight Losses and Corrosion Rates of Copper Sheet Specimens Exposed for 1, 2, and 5 Years in
Eight Canadian Atmospheres
Corrected Weight Losses (grams) and Corrosion Rate s trn, p. ｹｾ
Panel
1
yr of Exposure2
yrs of Exposure5
yrs of ExposureSite No. No. wt loss mpy wt loss mpy wt loss mpy
Ottawa
1
0.3237
0.5561
1.0517
(1)
2
0.3246
0.046
O. 5515
0.040
1.0367
0.029
3
0.3222
O. 5692
1.0030
Saskatoon1
0.1418
0.2109
0.3597
(2)
2
0.1823
0.026
0.1946
0.014
0.3749
0.011
3
0.2143
O. 1950
0.3779
Montreal1
0.3886
0.6337
1. 3845
(3)
2
0.3781
0.055
0.6238
0.045
1.3866
0.040
3
0.3860
0.6434
1.3837
Halifax1
1.0563
1. 6775
2.9950
(4)
2
1.0839
O. 151
1. 6376
O. 120
3.0451
0.085
3
1.0206
1.7118
2.9249
York1
0.4018
O. 5066
0.7938
Redoubt2
0.4129
0.058
O. 5369
0.037
0.8134
0.023
( 5)
3
0.4083
0.4944
0.7832
Norman1
O. 1134
O. 1104
0.2288
Wells2
0.1114
0.016
0.1210
0.008
0.2458
0.007
(6)
3
0.1058
0.1138
0.2606
Esquimalt1
O. 2916
0.5607
0.9909
(7)
2
0.3522
0.047
O. 5763
0.040
1.0883
0.030
3
0.3373
O. 5473
1. 0798
Trail1
O. 2934
0.7870
1.9344
( 8)
2
0.3249
0.044
O. 8031
0.057
1.9240
0.055
3
0.3161
0.8017
1. 8872
9
-TABLE III
Weight Losses and Corrosion Rates of Muntz Metal
Specimens Exposed for 1
t2, and 5 Years in
Eight Canadian Atmospheres
Corrected Weight Losses (grams) and Corrosion Rates(
m,p.
ｹｾPanel
1 yr of Exposure
2 yrs of Exposure
5 yrs of Exposure
Site No.
No.
wt loss
mpy
wt loss
mpy
wt loss
mpy
Ottawa
1
0.1902
0.4020
1. 1023
(1)
2
0'-1896
0.030
O.3899
0.030
1. 1263
0.033
3
O.1890
0.4023
1.0496
Saskatoon
1
0.0346
0.0707
0.2085
(2)
2
0.0362
0.068
0.0694
0.066
0.2155
0.063
3
0.0382
0.0700
0.2122
Montreal
1
0.4399
O.8763
2.0728
(3)
2
0.4381
0.068
0.8860
0.066
2. 1920
0.063
3
0.4737
O.8296
2.0043
Halifax
1
1.4316
2.8647
5.3371
(4;
2
1. 3910
0.213
2.7818
0.214
5.4455
0.164
3
1.4017
2.7581
5.4986
York
1
0.1922
ＰｾＳＸＷＴ1.0052
Redoubt
2
0.2006
0.030
0.3519
0.028
0.9821
0.030
(5)
3
O.1978
0.3683
1.0069
Norman
1
0.0061
0.0207
0.0970
Wells
2
0.0069
0.001
0.0201
0.002
0.0830
0.003
(6)
3
0.0070
0.0215
0.0848
Esquima1t
1
0.1246
0.2280
0.4364
(7)
2
0.1302
0.0198
0.2041
0.016
0.4487
0.013
3
0.1405
0.1992
0.4444
Trail
1
0.1978
0.4978
1. 1468
( 8)
2
O.1993
0.029
O.5078
0.038
1.1913
0.035
3
O.1919
O.5029
1.1776
o
01o
.
01o
01o
01 ｾ ｾ <.at ... '0 0) I ...wzl>""
c.n
<
-W-I
rn
G") I :I::::O C 0')rn l>
:::0ｾ
G")rn
l>'"
-I
3:l>
03:
000
""tJc ｾｺrn-l
:::c
rno
l>"
-100
rn c
l>1
n "
ｾｾc
oo:::tJ - 1 0rn -
o
" x
:::c-OO
3:
rTJI
I
I
I
I
IHALIFAX (4)
I
I
MONTREAL
(3)
I
TRAIL (8)
I
OTTAWA (I)
I
YORK REDOUBT (5)
0
SASKATOON
(2)
o
ESQUIMALT
(7)
]
NORMAN WELLS (6)
I
I
I
I
I
I
4·0
,....---...,.---.----r---.----...---.
ｾＲＮＩ
016L
o
0-0
0
2
3
4
5
6
EXPOSURE TIME - YEARS
( I ) OTTAWA
(2)
SASKATOON
(3)
MONTREAL
(4 )
HALIFAX
(5 )
YORK REDOUBT
3·0
(6 )
NORMAN WELLS
--I(7)
ESQUIMALT
w
z
(8 )
TRAIL
«
a.. < ,en
ｾ«
a:
(!)..
en
en
2·0
0 --I...
::r:::
(!)-w
3:
w
(!)«
a:
w
>
1·0
0«
FIGURE 2
WEIGHT
LOSS VS EXPOSURE TIME FOR COPPER
PANELS
( I ) OTTAWA
(2)
SASKATOON 0(3)
MONTREAL (4 ) HALIFAX5·0
(5)
YORK RE DOUBT(6)
NORMAN WELLS(7)
ESQUIMALT (8 ) TRAIL --I lIJ Z4·0
<t a.. <, it :E <tit
Q: <.!)3·0
..
en en 0 --I ｾ :::I: <.!) l&J ｾ l&J <.!) <t2·0
Q: l&J > <t ｾＷｌｯ l2)0
(6[0
2
3
4 56
EXPOSURE TIME - YEARS
