Fell.. 191;
T H E JOCR,VAL O F I N D U S T R I A L .1ND E N G I N E E R I S G C H E 3 1 I S T R Y
ORIGINAL PAPERS CORROSION OF INGOT IRON CONTAINING COBALT, NICKEL, OR COPPER‘ By HERBERTT . KALMUSA N D K. B. BLAKE.
There have been of late, in our technical journals, voluminous discussions a:; t o t h e cause a n d prevention of t h e corrosion of iron a n d steel. Dr. Walker3 says: “Corrosion is a n electrolytic phenomenon a n d can be understood b y electrical engineers on purely electrochemical grounds. It takes place a t ordinary temperatures only in t h e presence of water through t h e reaction Fe 2H‘+ Fe” 2H. This means t h a t a metallic iron a t o m electrically neutral interacts with z hydrogen ions present in t h e water and which carry electrical charges; t h e result is t h e production of a n iron ion which takes u p t h e two electrical charges from t h e hydrogen ions and t h e deposition of t h e t w o atoms of hydrogen. Energy is lost t o the surroundings a n d appears as electricity a n d heat.” I n general, t h e electrolytic theory of corrosion is accepted, according t o which t h e principal factors which influence corrosion are: ( I ) t h e number of hydrogen ions; ( 2 ) the intimacy of contact of t h e hydrogen ion with t h e iron; (3) t h e solution pressure of t h e iron; (4) t h e depolarizing action of oxygen; (5) t h e osmotic pressure of t h e iron ions. Nevertheless, with these general statements in mind, there is a certain amount of dissatisfaction with t h e application of t h e electrolytic theory, particularly as i t bears on prediction a n d remedy. Taking t h e electrolytic theory without further consideration, one would conclude t h a t homogeneity in t h e material insures protection from corrosion while heterogeneity enhances corrosion. While this is doubtless t r u e as one t e r m of t h e summation of causes which bring about corrosion, nevertheless, t h e other terms are of such importance as t o make this conclusion frequently contrary t o observation. Accepting t h e electrolytic theory, i t follows in t h e case of iron, other conditions being alike, t h a t t h e approach t o absolute freedom from impurities should a d d t o its resistance t o corrosion. It does not follow, however, t h a t of t h e metals technically produced, those analyzing t o have t h e least amount of impurities are t h e most non-corrosive, for other conditions are by no means always alike. Stresses or strains, even in a pure metal, produced b y uneven cooling of a
+
+
I Authors’ abstract of report to the Canadian Department of Mines, published by permission of the Director of Mines, Ottawa, Canada. This publication is one of a series on the metal cobalt and its alloys, particularly with reference to finding increased usage for them, which were conducted a t Queens University, Kingston, Ontario, for the Mines Branch, Canada Department of Mines. See also Tms JOURNAL,6 (1914), 107 and 115; 7 (1915). 6 ; 7 (1915). 379. * This paper was presented January 10, 1917, at the 9th Annual Meeting of the American Institute of Chemical Engineers in printed form. I n the absence of the authors it was read by title only. At the evening ses. sion extended comments and criticism of the paper were presented b y Dr. Allerton S. Cushman. Opportunity will be given in the March issue of THIS JOURNAL for presentation of the views of Dr. Cushman and any reply the authors may desire t o make.-THE EDITOR. 8 Tvansaclioizs of the .S?nerican Electrochemical Society, 29 (1916), 435.
A
casting or by rolling, whether hot os cold, provide unequal solution tension a t various points in t h e metal, particularly on the surface, and would thus promote corrosion. Also in t h e preparation of metals of high chemical purity, the resistance t o corrosion may be decreased by gas occlusion, or in other ways; in part due t o t h e very a t t e m p t t o attain t h e high degree of purity. Stresses a n d strains are usually partially or entirely overcome b y thoroughly annealing metals t o be used for sheet roofing materials, or for other purposes where corrosion is of great importance. The effect of t h e occlusion of hydrogen in steel has been shown by a number of investigators t o be very important, and, under certain conditions, t h e volume of this gas occluded will reach nearly 5 0 per cent of t h a t of t h e metal itself. I t is common knowledge t h a t t.wo metals when alloyed often have greater resistance t o corrosion t h a n either component metal alone. The principle applies to any number of components. This is probably always due t o t h e formation of some compound or compounds of t h e two metals, or under certain special conditions, i t might be due t o t h e combination of one alloying metal with t h e impurities of t h e other metal, in such a manner as t o cause t h e solution tension of t h e resulting compounds t o be about alike. The effect of alloying a second metal with iron or steel may also affect t h e corrosion of t h e original iron or. steel by increasing or decreasing t h e amount of occluded hydrogen. Another important effect of t h e introduction of t h e second metal may be t o form a n oxide, when corrosion commences, which is of such a n adherent nature as t o form a firm coating, inhibiting further corrosion or preventing a n excess of oxygen. Or, conversely, initial rusting may render t h e underlying iron anodic a n d may accelerate corrosion, perhaps in a large measure due t o t h e moisture held b y t h e rust. Thus, a great deal would depend upon whether or not t h e rust was soft and spongy or hard and adherent. We are inclined t o agree with those who consider t h e phenomena of corrosion more complex t h a n has been generally stated by enthusiastic adherents of t h e electrolytic theory. While this theory would seem sound as a guiding principle, much additional d a t a will be needed before i t can be amplified in detail to be accepted by engineers a n d practical men in general, as useful t o them in prevention a n d prediction. P U R P 0 S E 0F I N V E S T I G AT1 0 N
This investigation is primarily apart from theoretical considerations a n d explanations, having for its fundamental purpose measurement a n d the setting forth of data. Several long series of nieasurements extending over a period of years were made on t h e corrosion of American Ingot Iron as affected by t h e additions of small quantities of cobalt, nickel, copper
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
124
Vol. 9, KO. 2
a n d carbon. We have particularly in mind t h e addition of small quantities of these elements t o t h e very pure iron prepared by t h e open-hearth method for sheet roofing material. Our interest was stimulated by t h e positive nature of certain very early preliminary experiments described in t h e next paragraph.
were t h e same for all, and are given before t h e numerical corrosion values for t h e series. M A T E R I A L S F O R P R E P A R A T I O N O F ALLoYs-The base of all t h e alloys was American Ingot Iron: furnished b y Dr. Beck, American Rolling Mill Company, Middletown, Ohio, and analyzing as follows:
PRELIMINARY EXPERIMENTS
ANALYST Fe S P C Mn 'cu 0 Si h*i Ca Dr. Beck 99.9 0.023 0.004 0.010 0.031 0.028 0.035 Trace h-one None Authors 99.9 0.027 0.0075 0.010 0.027 0.048 . Trace None None
Very early in the course of these investigations on cobalt a n d its alloys (in t h e a u t u m n of r g ~ z ) a, preliminary set of alloys mas prepared b y adding small percentages of both cobalt a n d nickel t o very pure iron. These alloys mere exposed for several months on t h e roof of Nicol Hall, Queens University, Kingston, Ontario. After this exposure they were removed, a n d t h e amount of corrosion determined. I n every case i t was found t h a t t h e addition of small percentages of cobalt a n d nickel h a d decreased t h e corrosion of t h e pure iron.' Following this a second set of alloys was made with t h e same materials, in t h e same way, a n d exposed under t h e same conditions t s t h e previous set, for a period from June 16, 1913, t o October 16, 1913. At t h e end of this exposure of 1 2 2 days, t h e alloys were taken in, a n d t h e rate of corrosion in grams per sq. cm. of exposed surface per year was computed. Unfortunately, two of t h e alloys of this set met with accident during t h e exposure, owing t o dropping from t h e supports a n d coming in contact with t h e metal roof, so t h a t t h e series is not sufficiently complete t o warrant giving all t h e details. However, t h e results were in general accord with those of t h e previous set, which led us t o believe t h a t t h e addition of cobalt in proper proportions t o pure iron might prove of benefit t o its non-corrosive properties. The general method of procedure with these preliminary experiments was t h e same as t h a t described in detail for t h e complete set of experiments t o be described below. The two sets of experiments above described must be considered preliminary for a number of reasons, primarily because no heat treatment was given t o t h e alloys. CONCLUSIONS: I-From these preliminary experiments, i t appears t h a t additions of small percentages of both cobalt and nickel to American Ingot Iron a d d t o its non-corrosive properties. z-Cobalt seemed t o be more effective t h a n nickel when used in like amount. 3-These results were such as t o stimulate further interest, b u t were not sufficiently complete or satisfactory t o warrant drawing definite conclusions, particularly as t o t h e relative effects of nickel and cobalt. EXPERIMENTS
ON
NON-CORROSIVE
B Y ADDITIONS O F COBALT,
ALLOYS
SICKEL, AXD
PREPARED
COP-
PER T O AMERICAN I N G O T I R O N
Following are t h e d a t a of three extended series of observations, from which our conclusions are drawn. The materials used for t h e preparation of t h e alloys of all three series, a n d likewise t h e general procedure, I
The "pure" iron was American Ingot Iron.
..
Inasmuch as there has been some discussion in recent literature as t o t h e effect of copper in adding t o t h e non-corrosive properties of American Ingot Iron and similar materials, we have made, in addition t o t h e usual check analyses, additional analyses of t h e copper content. Checking our value of copper as 0.048, we have t h e following values from independent analyses: 0 . 0 4 6 , 0 . 0 4 j, 0 . o 50. These were made b y two independent analysts. A later analysis (by Dr. Beck) of American Ingot Iron rolled into sheets for roofing material a n d shipped t o this laboratory by t h e American Rolling Mills, Middletown, Ohio, is as follows: Sample Xo. 34175 (8' X 4') American Ingot Iron Corrosion
S
P
C
Mn
Cu
Sheet... 0.026 0.009 0.010 0 . 0 2 2 0.016 T h e cobalt, nickel a n d copper were of a correspondingly high degree of purity, analyzing, respectively, 99.7 per cent cobalt, gg. 3 per cent nickel a n d 9 9 . 8 per cent copper. T h e cobalt was prepared in this laboratory b y reduction of purified oxide,l and t h e copper and nickel were procured from reliable sources a n d analyzed in this laboratory as above stated. M E T H O D O F P R E P A R A T I O N O F ALLOYS C R U C I B L E A N D FURNACE-The alloys were all made in lined graphite crucibles obtained either from t h e Dixon Crucible Company or t h e Jonathan Bartley Crucible Company, a n d were either No. 3 or No. j size. These crucibles were lined with first-grade powdered magnesite, the magnesite being mixed with water t o bind i t until set. ,4 Hoskins electric furnace of t h e carbon plate resistor type was used for melting these alloys. M E L T I N G A N D CASTING-The components O f t h e alloy t o be prepared were weighed out a n d p u t into t h e crucible together. Often these went into a cold furnace t o be melted without pre-heating, while some were pre-heated in t h e Monarch Oil furnace previous t o putting t h e m into t h e hot electric furnace.* The temperature of t h e inside of t h e furnace was measured from time t o time, observations being made with a Wanner optical pyrometer. After t h e melt h a d received n-hat was considered a proper furnace treatment, powdered aluminum was added as a degasifier and i t was then poured into a n iron mold of variable depth which formed a cylindrical ingot about I . 2 5 in. in diameter. T h e alloys of Series I a n d I1 wcre cast in square molds of about t h e same volume. The casting usually weighed in the neighborhood of 2 lbs. The alloy was not considered satisfactory unless the crucible lining remained intact throughout, a n d 1 Canada Dept. of Mines, Bull. 209, 1913; THISJOURNAL, 6 (1914). 107.
* For a description of this furnace see Canada Dept. of Mines, Bull. 269,
1913.
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
126
Alloy Sample H 204
H 207 H
195
H 196 H
197
H
202
H 209 H 198
H 199
H 200 H 205 H 206 H 208 H
216
34175 34204 34196 34185 44009
Vol. 9, No.
2
TABLEI-RESULTS OF CORROSIONTESTS-SERIES I Exposed, March 18, 1914, ten o'clock. Removed, August 31, 1914. Exposure. 3984 hours CORROSION OF DISC Loss in DIMENSIONSOF DISC WEIGHT I N GRAMS Weight in Grams BEFORE EXPOSURE Original After Per sq. cm. APPROXIMATE ANALYSIS Diam. Thickness Area Before Removal Total per hr. Percentages No. Cm. Cm. Sq. Cm. Exposure of Rust Corrosion X 108 NATURE OF RUST Fe a 3.0053 0.5735 19.60 99.75 N i 0.25 31.7343 31.1464 0.5879 752 R u s t quite tenacious b 2.9353 0.4829 17.99 .. ... . 696 25.4387 24.9393 0.4994 Fe 99.5 N i 0.50 a 2.9972 0.5167 18.98 28.3184 27.9340 0.3844 R u s t quite tenacious b 2.6507 0.5299 15.45 22.7629 22.3216 0.4413 15.9782 15.5042 0.4740 C 2.4714 0.4335 12.96 Fe 99.0 Ni 1.0 a 2.9129 0.6670 19.433 34.7888 34.2410 0.5478 R u s t tenacious. Sample b had fallen off b 2.9126 0.6346. 19.132 33.0043 32.2974 0.7069 Fe 98.0 Ni 2 . 0 a 2.9515 0.6293 19.520 33.6308 33.1004 0.5304 R u s t removed somewhat easier than H 195 b 2.9538 0.6741 19.960 36.0536 35.5070 0.5466 Fe 97.0 Ni 3.0 a 2.9939 2.5960 19.687 32.4942 32.0300 0,4642 R u s t easily removed b 2.9756 0.4416 18.036 23.9081 23.4407 0.4674 652 Fe 99.75 C o 0.25 a 2.9068 0.3958 16.89 673 R u s t removed easier t h a n H 200. Sam. 20.4681 20.0148 0.4533 b 3.0148 0.3888 17.95 ple b had fallen off 775 21.5157 20.9614 0.5543 Fe 99.5 Co 0.5 a 2.7903 0.5974 17.47 793 Both samples off. Rust removed quite 28.4904 27.9386 0.5518 b 2.9556 0.5765 19.08 30.5810 30.2152 0 3658 easily. Sample b had not rusted 478 much on one side Fe 99.0 c o 1.0 a 2.9825 0.6615 20.172 36.2452 35.6630 0,5822 722 Rust dark in color and more tenacious b 2.9629 0.6225 19.685 33.5751 33.0090 0.5661 720 t h a n H 197 Fe c o 2.0 a 2.7545 0.6128 17.222 28.5496 28.0173 0.5323 774 R u s t dark in color and tenacious 98.0 b 2.9315 0.5527 18.590 29.2209 28.6635 0.5574 768 R u s t dark in color a n d quite tenacious Fe c o 3.0 a 3.0368 0.5592 19.82 31.5005 31.1169 0.3836 97.0 482 R u s t dark in color and quite tenacious 31.0141 30.5259 0.4882 b 3.0178 0.5533 19.55 627 'Fe a 2.8759 0.5433 17.90 27.5937 27.0692 0.5245 99.75 c u 0.25 738 R u s t about t h e same as H 204 b 2.8853 0.5895 18.42 734 30.1322 29.5943 0.5379 Fe c u 0.5 a 2.9472 0.5497 18.73 99.5 761 R u s t about the same a s H 204 29.2453 28.6776 0,5677 b 2.9459 0.5579 18.81 748 29.6137 29.0536 0.5601 Fe 99.0 a 2.3835 0.7078 14.23 816 R u s t removed rather easily c u 1 .o 24,3692 23.9062 0 4630 b 2.3772 0.6475 13.71 835 22.3719 21.9154 0.4565 F e 100.0 a 3.6021 0.5611 26.73 968 R u s t quite easily removed. Sample a 44,8356 43.8024 1.0332 b 3.7567 0.6153 29.43 937 had fallen off 53.3836 52.2870 1.0966 S 0.027 P 0.0078 C 0.131 a 3.769 664 R u s t removed very easily 1.118 35.37 97.6351 96.7020 0.9331 0.027 c u 0.020 Mn 701 R u s t removed very easily b 3.683 1.118 34.18 93.2952 92.3370 0.9582 Co 0 . 2 2 M n 0.036 c u 0.020 a 3 . 7 1 8 118 R u s t more tenacious than 34175, but 1.047 33.95 89.1774 87.5760 1.6014 0.022 P 0.0058 C 0.125 S less tenacious t h a n 34185 -All b 3.698 1.049 33.32 88.3738 87.9770 0.3968 LYL Co 0.57 Mn 0.031 c u 0.021 a 3.723 640 R u s t tehacious; not very different from 1 , 1 0 1 34.32 94.0772 93.2020 0.8752 97.4638 96.5120 0.9518 S 0.025 P 0.0097 C 0.156 b 3.735 678 34204 1.135 35.22 Co S Ni S
1.09 0.027 0.70 0.020
Mn P Mn P
0.032 0.008 0.025 0.0065
C u 0.025 C 0.145 C u 0.27 C 0.140
a
b
a b
3.682 3.712 3.728 3.739
1.105 1.091 1.014 1.063
34.20 34.22 33.75 34.50
prepared for exposure in t h e manner described. T h e results appear in Table 11. CONCLUSIONS: I-Results with t h e set of alloys, numbers 196 t o 216, show t h a t in every case t h e alloy formed by the addition of cobalt, nickel or copper is less corroded in t h e atmosphere t h a n is American Ingot Iron. These are unannealed samples. 2-Concksion ( I ) for Series I1 is in accord with the corresponding conclusions for Series I. Comparing t h e absolute amounts of corrosion (loss in weight in grams per sq. cm. of original surface per hour) we find t h a t it is uniformly greater for Series I t h a n for Series 11, approximately in the ratio of 3 t o 2 . This may be in some measure accounted for by t h e fact t h a t t h e exposure for Series I was largely in t h e summer time, whereas t h e exposure for Series I1 was both in summer a n d winter. It is more t o be accounted for, however, by t h e fact t h a t the exposure for Series I1 was of very nearly twice t h e duration t h a t it was for Series I. After corrosion has continued for a certain period, especially with t h e more non-corrosive alloys, a hard, tenacious, dark-colored rust is formed which tends t o protect t h e alloy against further corrosion. 3-The variations in the measurements are not so great b u t t h a t Conclusions ( I ) a n d ( 2 ) are apparent, b u t t h e variations are sufficiently great t h a t comparisons between the various alloys cannot be drawn without further confirming measurements t o establish the law. 4-Samples Nos. 34,175 t o 44,009, prepared b y the American Rolling Mill Company, so far as this series alone is concerned, do not tend t o bear out the
92.2378 92.5329 86.8718 91.4208
91,1260 91.7200 85.8190 90.2970
1.11 18 0.8129 1.0528 1.1238
823 R u s t very tenacious 613 R u s t very tenacious 783 R u s t verv tenacious, not unlike 34185 819
conclusions from the series prepared a t t h e laboratory. From these samples alone it would seem t h a t additions of small amounts of cobalt, u p t o one per cent, have very little effect on corrosion, a n d t h a t t h e addition of nickel t o about 0 . 7 per cent was harmful. 5-It is noticeable throughout this series, for t h e samples prepared a t t h e laboratory, t h a t additions of cobalt, nickel a n d copper all tend t o make the rust more tenacious, darker in color, more uniform, a n d very much more difficultly removed by mechanical means t h a n is t h e case with the pure American Ingot Iron. This fact is particularly noticeable with t h e cobalt samples. CORROSION TESTS-SERIES
111
(Microphotographs made)
The samples of Series I and I1 received no heat treatment after casting. For further investigation Series I11 was prepared; a list of the alloys of this series with t h e method of preparation appears in Table I I I A , page 130. F U R N A C E TREATMENT-In this Series Of alloys some of t h e charges were preheated in t h e Monarch Oil Furnace and some were introduced directly into t h e hot Hoskins Furnace. T h e d a t a of preparation of two alloys by each t r e a t m e n t are given in detail. All samples of this series were prepared b y one or the other of these methods as indicated. Any variation from these will be noted under t h e individual charge. Samples were prepared from these alloys in t h e manner previously described a n d mounted for exposure on t h e roof of Nicol Building, Queens Uni-
T H E JO U R N A L 0 F I A’ D C S T RI A L A N D E N G I 117 E E R I N G CH E M I S T R Y
Feb., 1917
H 204 F e H 207 F e
H 195 F e
TABLE 11-RESULTS OF CORROSION TESTS-SERIES 11 Exposed, October 10,1914. Removed, August 30,1915. Period of Exposure, 7776 hours CORROSION OF DISC Loss in DIMENSIONSOF DISC WEI,GHTIN GRAMS Weight i n Grams BEFORE EXPOSURE Original After Per sq. crn. APPROXIHATEANALYSIS Diam. Thickness Area Before Removal Total per hr. Percentages No. Cm. Cm. Sq. Cm. Exposure of Rust Corrosion X 10s NATURE OF R u s r 99.75 N i 0.25 a 2.984 0.540 17.59 28.9636 28.2924 0.6712 491 Difficult t o remove. Dark Mottled appearance b 2.918 0.453 16.70 22.9425 22.3325 0.6100 470 99.5 N i 0.5 a 2.980 0.487 18.49 26.1491 25.5458 0.6033 420 Fairly tenacious 13.66 20.0225 19.5246 0.4979 470 b 2.621 0.481 99.0
Ni
1.0
c
2.480
a
2.898
0.401
12.76
14.3902 13.9915 0.3987
196 F e
98.0
Ni
2.0
Ni
3.0
b a b
0.600
18.25
30.0960 29.2932 0.7268 Without wax
2.759 0.550 2.938 0.534 2.965 0.616 2.940 0.590 2.730 0.584 2.911 0.522 3.022 0.535 3.002 0.528 2.853 0.516 2.865 0.557 2.918 0.515 2.918 0.520 2.353 0.673 2.350 0.616 3.578 0.522 3.732 0.584 2.897 0.769
16.72 18.51 19.59 19.03 16.74 18.09 19.45 19.08 17.38 17.93 18.07 18.12 13.65 13.20 25.97 28.66 20.12
2.561
0.768
16.42
30.5996 29.8434 0 7562
2.293 2.050 3.952
0.770
0.766 0.767
13.70 11.47 34.00
24.5528 23.9235 0.6293 591 19.3758 18.8358 0.5400 605 73.1770 71.6381 1.4989 567
c
3.700 3.470 3.180 2.930
0.773 0.768 0.766 0.769
30.31 26.73 23.02 20.50
64.5962 55.1002 47.2278 40.2700
63.1962 53.9060 46.1447 39.3239
1.4000 1.1942 1.0831 0.9461
594 604 562 593
b
2.672 2.438 2.171 3.810
0.766 0.766 0.763 0.773
17.56 15.15 12.53 32.03
33.1640 27.7012 21.7768 68.4924
32.3249 26.9839 21.2004 67.1646
0.8391 0.7173 0.5764 1.3278
613 609 592 534
3.553
0.774
28.48
59.6462 58.4286 1.2176
551
3.318 3 068 3.313
0.770 0.769 1.025
25.22 22.14 17.44
51.6070 50.5487 1.0583 44.1810 43.2005 0.9805 69.1338 68.0’4’671.0574
570
3.065 1.027 2.812 1 032 2.560 1.026
14.95 12.64 10.47
58.9434 58.0252 0.9182 49.8336 48.9872 0.8464 41.0208 40.3029 O.lli9
788 860 883
a
97.0
97.75 C o 0.25
209 F e
99.5
Co 0.5
a
198 Fe
99.0
Co 1.0
a
199 F e
98.0
Co 2.0
a
200 F e
97.0
Co 3.0
a
205 F e
99.75 Cu 0.25
H 206 F e
99.5
C u 0.5
H 208 F e
99.0
Cu 1 . 0
H 216 Fe
100.0
34175 S 1Mn S
Mn
b a
b b b b a b a
b a
b
0.027 P 0.027c u 0.027 P 0.027 Cu
a
b a
0.0078 C
0.131
0.0078 C
0.131 b
0.020 0.020
G
34204 Co
S
d 0.22 M n 0.036 Cu 0.020 a 0.022 P 0.0058 C 0.125 b
34196 Co
S
d 0.57 M n 0.031 Cu 0.021 a 0.025 P 0.0097 C 0.156 c
34185 Co
S
Co
S
1.09 M n 0.027 P 1.09 M n 0.027 P
d
0,032 Cu 0.025 a 0.008 C 0.145 0.032 Cu 0.025 b 0.008 C 0.145 c
44009 Ni
S
512 Rust tenacious; somewhat dark after removal of rust
18.53 19.08 19.43 19.18 17.58 16.43
197 F e
d
0.700 M n 0.025 Cu 0.270 a 0.020 P 0.0065 C 0.140 b c
d
spots.
402
0.571 0.588 0.641 0.561 0.412 0.371
202 F e
in
With wax in holes
m n7nn
H H H H H H H H
127
2.893 2.938 2.940 2.982 2.961 2.885
versity, Kingston, Ontario. This series was mounted in t h e same may as Series 11, a n d t h e duration of exposure was 253 days, 3 hours, beginning December 22, 1914,1 . 1 5 P . M . t o December 23, 1914, 4 - 3 0P . M . time ending September I , 191j,4.15 P.M. t o September 2, 191j,7.30 p.11. Total hours, 6,075. In addition t o t h e samples prepared as above described, another set of samples mas prepared from the American Rolling Mill Company alloys, and given a similar heat treatment. After having been exposed t h e samples weie brought in a n d carefully freed from rust and final measurements made as noted in Table 11123. Microphotographs of this series are shown on pages 128, 129, 132 and 133. A C C E L E R A T E D CORROSION TESTS-SERIES
IV
A few accelerated corrosion tests were made on some of these alloys, t h e results of which may be instructive, although not conclusive. As t o v-hat would occur under service conditions in t h e atmosphere, t h e authors do not believe t h a t much reliance can be placed upon conclusions drawn from accelerated
29.0754 30.9354 23.7160 30.2280 21.8434 18.7266
28.4344 30.2866 33.0554 29.6297 21.2940 18.2327
0.6410 0.6488 0.6606 0.5983 0.5494 0.4939
445 437 Rust easily removed: light in color 437 401 Rust easily removed; light in color 402 386 Rust dark. tenacious. and uniform over
24.8650 27.1625 32.2596 29.8162 25.7902 26.1593 27.8894 28.2609 24.5636 26.8236 26.0090 26.2528 21.9834 20.0884 39.5724 48.1793 35.7888
0.6495 0.6253 0,7590 0.7018 0.6364 0.6771 0.5392 0.5497 0.5718 0 . ,5932 0.6208 0.6222 0.4112 0,4034 1.2256 1 ,5545 0.9122
435 Rust medium dark in color 500 498 Rust dark in color; fairly difficult t o 475 remove 489 Medium dark in color 482 356 Rust easily removed; metal underneath 371 dark in color 414 R u s t hard in spots, metal underneath 415 dark in colox 443 Rust light in color; metal underneath 442 rn _i t_t _d_ _ 387 Rust very uniformly distribnteti and 392 difficult to remove 608 Rust easily removed 698 583 Rust light in color and fairlv easily re-
surface
move2
592
H;
-:
539 7i9
tests. These measurements are included with the rest for completeness. Accelerated corrosion tests were made on t h e five heats of Ingot Iron alloys submitted by t h e American Rolling Mill Company, as follows: No. 34175 S 0.026 P 0.009
c
0.010
M n 0.022 Cu 0.016
Iio. 34185 S 0.034 P 0.006 C 0.015 M n 0,017 Cu 0.028 Co 1.18
No. 34196 No. 34204 S 0.040 s 0.022 P 0 . 0 0 8 P 0.009 c 0.010 c 0.010 M n 0.020 M n 0.020 Cu 0.024 c u 0.020 Co 0.60 c o 0.35
No. 44009
S P
c
0.02.5 0.008
0.010 M n 0.015 Cu 0.24 Ni 0.75
M E T H O D O F M A K I K G ACCELERATED CORROSION T E S T S
These tests were made either by ( a ) immersing t h e samples in t h e form of spheres in a dilute sulfuric acid for a period of I hour a n d noting t h e loss in weight, or, ( b ) submitting , t h e m t o t h e intermittent action of dilute sulfuric acid a n d t h e atmosphere. The acid used for t h e tests was 2 0 per cent H?S04. Samples were used throughout in t h e form of spheres of approximately 7 sq. cm. surface. The intermittent corrosion tests mere made by immersing the samples in t h e acid in one compartment of a wooden box, so arranged t h a t t h e samples
P.LLOY Baoa Cb c Fe 0.25 o.1~
97.5
A L L O Y 23/98 G
e
LO
5.3s
l
5 94.6
A L L O YC d ~ o i
e,
0.25
c
6 0.49 99.2
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
Vol. 9, No, a
TABLEIIIA-COMPOSITION
AND HEAT TREATMENTS OF A L L O Y S ~ E R I EI11 S FURNACE: HOSKINSRESISTORFURNACE,TYPEF. C. No. 105 ALUMINUM CRUCIBLE:No. 3 GRAPHITE, MAGNESITE-LINED. DEGASIFIER: 0.2 G. POWDERED HEATTREATMENT: ANNEALEDB Y HEATINGI N GAS MUFFLE FURNACE AT 870' FOR 2 HRS.,AND ALLOWING TO COOL SLOWLY WITH FUXNACE
CHARGES (IN GRAMS)USED IN M A E :ING ALLOYS *Fe co
-B -Bz
199-
-s
250-
-S
262-
S 262 co
*Fe
202-
co
S 260
B 200 Pure Co
s
255-
252 *Fe co -S 265Alloy 32404 co -B 209B 202 co -s 252250 co -S 2 6 0 *Fe B 200 -S 2 6 6 Alloy 34204
s
Co
-B B 202 B 209 co
603 6.15 778 1.95
B 30 *Fe co
198-
-B; 2 0 0 -
375.5 594 1.53
*Fe
467 0.16
*Fe Ni
63 7 1.54
*Fe Ni
650 1.55 576 192 467 2.35
-c
202-
-s
251-
-s
254-
-s
305 85 85 0.69 65 1 0.65
743 1.86
257226 495 1.72
--S
258-
--S
259-
*Fe Ni
BI 199 340 *Fe 262 co 11.63 *American Ingot Iron.
255 255 1.28
913 3.19
*Fe hri
326 460 4.80
482 1.49
1132 2.85
Pure Ni
S 254
935 4.67
S 258 Ni -Bz S 261 Ni -S S 261 Ni
-s
269-
-S C 204 *Fe Ni -S B 30 *Fe ~. Ni -B B 207 Ni
267-
2 0 h
-c 255c 202 B 30 Alloy 32404 co -B 199B 198 co -B 2 0 4 -
45 6 226 130 0.49
s 255
-s
-B B 199 co
1132 2.85
637 1.60 195177 160 263637 6.50
*Fe Ni
-E
B 195 Ni -Bz S 263 B 197 Ni
*Fe Ni
C
566 11.58
268127
467 ...
2.99 195800 4.04 1 9 6
680
6.95 197-
-c
204-
-B,
205-
-B
205-
*Fe cu *Fe cu
....
Preheat 0il TEMP.(OC.) OF Wt. of Furn. Soaking Melt Pour- Casting F e Min. Min. O C . (Max.) ing Oe.
326 436 1.09
-B 197-
B 196 Ni
Alloy
COMPOSITION Percentages
184 368 1.90 517 5.33 269.5 1.35 1.062 2.66
-Bz 206-
Bs 205
552 1.39
cu
-B B 205 cu -B Bz 206 *Fe cu
793 0.25
2 0 6
488 1.23
208318 279.5 4.40
were covered a n d uncovered automatically by t h e tilting of this box over a knife edge pivot b y t h e action of water from t h e water tap. T h e balls were held in place a t one end of t h e box by pieces of glass rod. T h e apparatus used for making these corrosion tests consisted of a wooden box 18 in. long a n d 1 2 in. wide, with sides about 3 in. high. This box was divided into 2 lengthwise compartments, one larger t h a n t h e other, t h e large one being still further divided into 2 equal compartments; this division was across t h e narrow way of t h e box directly in t h e middle, t h e
dividing board extending well above t h e edge of t h e box. Across t h e outside of t h e bottom of t h e box in t h e middle a wooden knife edge was fastened. T h e operation was somewhat as follows: T h e s a m ples were placed in one end of t h e undivided lengthwise compartment, supported a n d held in place b y glass rods, a n d covered with t h e corroding solutions. This unbalanced t h e box so t h a t it inclined t o one side keeping t h e samples under t h e solution until the box was tilted t o t h e opposite side. This tilting was accomplished b y opening t h e water t a p above t h e
TABLE IIIB-RESUL ,TS OF CORROSIONTESTSO N ALLOYS-SERIES 111 CORROSIONos DISC DIMENSIONS'OF DISC BEFORE EXPOSURE WEIOHTIN GRAMSI,OS in Weight in Grams ThickOriginal After per sq. Before Removal Total cm. per Area APPROXIMATEANALYSIS No. Diam. ness Alloy NATUREOF RUST Corrosion hr. X 101 Cm. Sq. Cm. Exposure of R u s t Percentages Sample (e) Cm. 0.5215 512 R u s t light in color and fairly hard t o remove 15.4919 14.9704 2.898 0.303 16.78 s 250 F e 99.6 C 0 0 . 2 5 C 0 . 0 8 3 e 0.6279 635 R u s t fairly light in color and easily removed 22.2445 21.6166 a 2.787 0.473 16.25 B 202 F e 9 9 . 5 C o 0 . 2 5 C 0 . 1 8 0.6663 604 33.5618 32.8955 b 2.755 0.731 18.17 0,4495 499 R u s t medium dark in color a n d very tenacious 18.1622 17.7127 c 202 F e 99.2 CoO.25 C 0 . 4 9 a 2.690 0.415 14.83 0.3921 498 16.0172 15.6251 b 2.480 0.430 12.97 0.3589 484 20.1774 19.8185 e 2.181 0.709 12.24 c 202 0.5299 493 R u s t light in color and fairly hard to remove 17.4452 16.9153 a 2.022 0.363 17.72 255 F e 9 9 . 4 (200.35 C 0 . 2 1 0.5026 475 17.8454 17.3428 b 2.988 0.368 17.42 0.4898 542 14.7667 14.2769 C 2.781 0.320 14.90 0.5773 ' 534 24.0373 23.4600 e 2.940 0.463 17.80 0.7654 659 R u s t easily removed 32.6708 31.9054 a 2.918 0.640 19.11 S 265 F e 9 9 . 3 C o 0 . 3 5 C 0 . 3 0 0.7660 643 35.2712 34.5052 b 2.920 0.688 19.62 0.7712 649 33.7064 32.9352 2.920 0.660 19.55 0.6765 622 30.7998 30.1233 2.747 0.710 17.92 0.5264 562 R u s t difficuIt t o remove 21.3656 c 255 F e 9 9 . 2 CoO.35 C 0 . 4 9 a 2.655 0.526 15.40 21.8920 0.4074 560 11.2287 10.8213 b 2.478 0.309 11.98 0.4094 585 19.6978 19.2884 2.247 0.656 12.52 E 0.6530 607 R u s t hard t o remove 27.1690 26.5160 a 2.873 0.550 17.75 B 209 F e 99.2 C 0 0 . 5 0 C 0 . 2 7 0.6032 863 26.9648 26.3616 b 2.620 0.652 11.50 0.6068 875 19.8818 19.2750 11.42 2.810 0.425 C 0.4686 479 R u s t medium dark in color, tenacious 22.2329 s 252 F e 9 9 . 1 C 0 0 . 5 0 C 0 . 3 1 a 2.747 0.500 16.11 22.7015 0.4454 487 19.2264 18.7810 b 2.692 0.440 15.07 0.4690 493 18.7750 18.3060 2.764 0.406 15.66 C 0.5345 500 R u s t dark in color and quite difficult t o remove 25.7013 25.1668 a 2.881 0.510 1 , . 5 9 S 260 F e 99.1 C o 0 . 7 5 C 0 . 1 7 0.4822 502 25.4463 24.9641 b 2.628 0 , 6 0 6 15.79 0.5297 472 27.7345 27.2048 2.854 0 . 5 6 4 18.51 0.4761 527 19.5841 19.1080 2.680 0.448 14.86 0.4586 507 22.0557 21.5971 2.582 0.553 14.92 0.4819 492 16.0904 15.6085 f, 2.806 0.337 16.12
s
2
2
Feb., 1917
TH.E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y TABLE IIIB-RESULTS OF CORROSION TESTSO N ALLOYS-SERIES 111-(Concluded)
Alloy Sample S 266
F e 99.0
APPROXIMATE ANALYSIS Percentages Co0.75 C0.21
B
198
F e 98.6
Co 1 . 0
S 262
C0.38
F e 98.3
Co 1.0
C0.62
Ba 199 F e 97.8
C02.0
C0.16
B
C02.0
C0.46
B; 200 F e 9 6 . 8 c 0 3 . 0
C0.17
B
200
F e 96.6
Co 3 . 0
C 0.36
S
251
F e 99.6
N i 0.25
C0.057
199
Fe97.5
B 204
F e 99.6
Ni 0.25
c 0.10
S
267
F e 99.5
Ni 0.25
C 0.23
C
204
Fe 99.5 Fe 99.3
Ni 0.25 hTi 0 . 2 5
C 0.23 C 0.43
S
254
F e 99.6
N i 0.35
C 0.045
S
257
F e 99.6
Ni0.35
C0.060
S
258
F e 99.4
Ni 0.50
CO.072
S
268
F e 99.2
N i 0.50
C 0.21
S
259
F e 99.2
Ni 0 . i 5
C0.067
S 263 F e 9 8 . 9 N i 1 . 0 BI 195 F e 98.9
N i 1.00
C 0.065 C 0.089'
B
195
Fe 98.8
N i 1.0
C 0.24
S
269
F e 97.9
Ni 2.0
C 0.085
B
196
Fe 97.8
Ni 2.0
C0.23
Ba 197
Fe 96.8
Ni 3.0
C0.13
B
197
Fe 56.7
Ni3.0
C0.21
Br 205
F e 99.7
Cu0.25
C0.045
205
Fe99.6 Fe99.6
CuO.25 Cu0,25
C0.19 C0.19
B
Ba 206
F e 59.3
Cu0.50
C0.17
CORROSION OF DISC DIMENSIONSOF DISC BEFORE EXPOSURE 'WEIGHT I N GRAMSLoss in Weight in Grams per sq. Original After ThickArea Before Removal Total cm. per No. Diam. ness Corrosion hr. X 108 NATUREOF RUST (e) Cm. Cm. Sq. Cm. Exoosure of R u s t 0.2762 555 R u s t quite dark and difficult t o remove 1i.5887 11.3125 a 1.863 0.567 8.20 0.4837 488 25.4683 24.9446 b 2.705 0.580 16.35 24.1817 23.6588 0.5229 530 c 2.733 0.542 16.24 0.5214 d 2.720 0.564 16.35 25.1076 24.5862 525 0.6047 615 R u s t difficult t o remove 31.7021 31.0974 a 2.757 0.692 16.20 20.4550 19.9428 0.5122 545 b 2.712 0.467 15.45 23.9154 23.3908 0.5246 539 c 2.703 0.547 16.04 0,3902 a 2.632 0.370 13.88 15.4269 15.0367 463 R u s t dark in color and hard to remove 0.4719 514 c 2.865 0.403 15.11 20.8344 20.3625 45.6640 44.9795 0.6845 686 R u s t coarse-grained, easily removed b 2.597 0.930 16.44 29.9907 29.4516 0.5391 495 c 2.780 0.672 17.94 a 2.857 0.662 16.56 32.6886 32.0577 0.6629 659 R u s t fairly difficult t o remove 0.4931 49 1 b 2.655 0.668 16.55 28.3872 27.8941 e 2.780 0.635 17.60 29.6310 29.1169 482 0.5141 c 1.473 0 . 7 8 6 8.29 10.1161 9.8990 433 0.2171 a 2.900 0.373 16.57 18.9260 18.4505 473 R u s t medium dark in color; fairly coarse0.4755 grained 476 b 2.880 0.530 17.77 24.0182 23.5044 0.5138 448 e 2.882 0.513 17.86 25.7456 25.2590 0.4866 0.3678 25.6795 25.3117 425 R u s t dark in color, difficult t o remove a 2.354 0.764 14.27 8.97 0.2286 b 1.857 0.624 12.8862 12.6576 420 0,2830 c 2.386 0.564 13.10 19.1863 18.9033 446 Exposed 4839 hours a 2.905 0.734 19.92 37.8434 37.1360 0.7074 585 Rust very loose b 2.772 0.587 17.14 27.4977 26.8967 0.6010 578 592 e 2.893 0.782 20.15 39.7612 39.0367 0.7245 a 2 830 0.611 17.94 29.3386 28.7089 0.6297 578 Rust coarse-grained; easily removed b 2.568 0.552 15.10 21.8389 21.3033 0.5356 585 a 2.730 0.464 15.54 63 7 R u s t dark in color and difficult t o remove 20.7134 20.1127 0.6007 b 2.750 0.329 14.67 14.9593 14.4270 0,5323 598 c 2.740 0.575 l h . 6 4 25.8113 25.2424 0.5689 563 d 2.762 0.510 16.34 23.1425 22.5593 0.5832 588 R u s t dark in color and difficult t o remove a 2.763 0.446 15.52 18.0503 17.5485 0.5018 522 Rust fairly loose and light in color b 2.770 0.653 18.00 29.8952 29.3469 0.5483 502 c 2.850 0 667 18.62 502 32.3107 31.7437 0.5670 a 2.832 0.493 16.96 555 Rust coarse-grained on surface but fine23.8922 23.3215 0.5707 grained below b 2.797 0.662 16.37 0.6189 623 30.9796 30.3607 e 2.P20 0.633 16.39 30.1311 29.5109 0.6202 623 a 2.818 0 . 3 9 0 15.88 18.6770 18.1632 0.5138 533 R u s t medium in color and quite tenacious b 2.820 0.421 16.18 20.1592 19.6374 0.5218 531 a 2.905 0.362 16.50 18.5816 18.0294 0.4522 45 1 R u s t very dark in color and removed with great difficulty e 2.885 0.543 17.92 27.2468 26.7670 0.4798 442 a 2.479 0.579 14.04 21.4394 21.0221 0.4173 489 R u s t medium dark in color m d quite finegrained b 2.119 0.555 10.64 476 14.8062 14.4988 0.3074 e 2.780 0.570 17.09 26.5809 26.1139 557 Exposed 4896 hours 0.4670 a 2.905 0.532 18.02 27.2486 26.6656 533 R u s t fairly loose and light in color 0.5830 b 2.865 0.425 16.b3 547 0.5518 21.0132 20.4614 c 2.949 0.344 16.111 0.5784 18.0560 17.4776 565 d 2.780 0.464 1 6 . i 3 533 21.6476 21.1233 0.5243 e 2.901 0.596 18.56 30.4007 29.8090 0.5917 525 e 2.939 0.337 16.56 455 R u s t dark and very hard t o remove 17.5516 17.0942 0.4574 a 2.875 0.339 16.16 16.9031 16.4033 0.4998 509 R u s t dark in color and hard t o remove b 2.802 0.637 17.07 495 30.3503 29.8193 0.5310 e 2.882 0.512 17.65 25.6145 25.0789 0.5356 500 b 2.710 0.449 14.84 470 R u s t very dark in color and difficult t o remove 19.9142 19.4903 0.4239 e 2.820 0.585 17.57 462 28.2365 27.7448 0.4917 a 2.920 0.345 16.51 488 R u s t dark in color, coarse-grained and hard 17.6610 17.1717 0.4893 t o remove b 2.880 0.574 18.12 27.4780 26.9605 0.5175 470 e 2.924 0.583 18.72 29.1942 28.7006 0.4936 538 Exposed 4896 hours a 2.865 0.638 18.57 31.7648 31:2547 0.5101 452 R u s t dark, fine-grained and quite tenacious b 2.810 0.720 18.69 34.5114 34.0049 0.5065 447 c 2.696 0.645 16.30 28.2857 27.8783 0.4074 495 a 2.938 0.361 16.78 18.3561 17.9187 0.4374 429 R u s t very dark and fine-grained; quite tena-
b c
e
3.238
0.734
23.84
46.9786
46.2114
0.7672
638
b
2.959
0.823
21.34
44.0585
43.3660
0.6925
643
45.4052 48.9962 55.6110 53.8524 55.0917 54.8672 55.3730 60.5641
44.6974 48.2394 54.6935 53.0112 54.0661 53.8681 54.4791 59.7725
0.7078 0.7568 0.9175 0.8412 0.9256 0.9991 0.8939 0.7916
638 638 640 582 613 706 624 522
59.6150 0.8270 60.8444 0.8301 61.9945 0.8279 American Ingot Iron.
533 532 535
a
b c a b c d
a
b e a
b
B 206
F e 99.3
Cu0.50
C0.19
e a
b
B
208
Fe 9 9 . 0
CuO.75
CO.18
c a
b AMERICANROLLINQMILL SAMPLES 34204 *Fe 9 9 . 6 C o 0 . 3 5 CO.01 a * F e 9 9 . 6 CoO.35
CO.01
34196
*Fe 99.3 C o 0 . 6 0
c 0.01
34185
*Fe 9 8 . 8 Co 1.18
c 0.01
ClOUS
2.952 0.232 2.818 0.224 2.733 0.621 2.740 0.436 2.679 0 . 5 6 8 2.520 0.497 2.768 0.464 2.757 0.283 2.790 0.584 2.790 0.653 2.800 0.663 2.783 0.565 2.777 0 . 5 5 6 2.665 0.674 2.805 0.586 2.833 0.573 2.833 0.734 2.940 0.697 2.570 0.524 2.620 0.272 2.960 0.537
15.77 14.39 16.94 15.45 15.93 13.94 16.02 14.33 17.22 17.85 18.10 17.05 16.85 16.73 17.44 17.59 18.94 19.92 14.51 13.81 18.54
b 3.180 0.977 25.53 c 3.172 1.000 25.70 d 3.185 1.011 25.47 tThese samples were mounted February 4, 1915, a t 2.35 P.M.
0.4276 0.3830 0,4093 0.3621 0.3666 0.5586 0.6646 0.6211 0.7335 0.5222 0.5256 0.4517 0.4500 0.4500 0.4689 0.5153 0.5501 0.5520 0.4.575 0.4160 0.5534
60.4420 61.6745 62.9224
*
446 438 398 386 379 663 683 712 701 482 478 541 440 443 443 482 478 456 519 497 492
R u s t very dark in color R u s t very loose and light in color
R u s t fairly dark in color and tenacious Exposed 4896 hours Rust light in color and difficult t o remove R u s t light in color and loose R u s t dark in color and fairly tenacious
R u s t light in color and fairly tenacious. Exposed 5043 hours R u s t light in color and fairly tenacious. Exposed 5043 hours R u s t light in color, scaly
R u s t medium in color and fairly difficult t o remove. Exposed 6018 hours; found on roof
(e) Etched for microphotograph.
ALLOY 1.0
SZb3
C
FA
O.Ob5
90.9
A L L O YB NI
C
197 Fa
3.0
o.at
96.7
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
134
Vol. 9, No.
2
either t h e one containing more ( I . 18 per cent) or t h e one containing less ( 0 . 3 5 per cent cobalt). CORROSION TESTS, AMERICAN INGOT I R O N ALLOYS I N THE FORM OF S H E E T ROOFING MATERIALS-SERIES
V
I n addition t o t h e numerous corrosion experiments on discs of t h e alloy above mentioned, there were atmospheric corrosion tests made on sheets of these alloys under service conditions. Pure cobalt of t h e supply mentioned on page 124 was sent from this ,laboratory to t h e American Rolling Mill Company, Middletown, Ohio, early in 1913. It was arranged t o make u p charges in their 4-ton experimental furnace, such as could be rolled into full-sized roofing sheets t o be subjected t o t h e usual corrosion tests. Three such cobalt alloy sheets were sent t o this laboratory, together with a r u n similarly prepared, using monel metal in place of cobalt a n d a
P
630 530
430
330
laboratory for 5 hours a n d 5 minutes. Immersion a n d exposure were each divided into I Z approximately equal intervals, t h e twelve 41/2-minute immersions with t h e corresponding twelve exposures constituting t h e corrosion test, which was repeated with t h e same set of spheres. It will be seen from Tables IVA a n d B TABLE IVB-ACCELERATEDCORROSION TEST, MAY26, 1914 Sample No. 34175 34185 ,34196 34204 44009
Surface sq. cm. 7.953 7.808 7.421 7.376 6.867
GRAMS Corrosion per Final Loss sq cm. per hr. 8.3033 0.0166 0,00232 7.8352 0.0180 0.00256 6.7386 0.0144 0.00216 6.6222 0.0152 0.00229 5.3404 0.0079 0.00216
WEIGHT I N
Original 8.3199 7.8532 6.7530 6.6374 5.3483
t h a t t h e two sets of measurements agree very well among themselves a n d t h a t t h e order of passivity of t h e alloys is as follows: 44,009; 34,196; 34,204; 34,175; 34,185. . For comparison with t h e above, t h e standard sulfuric acid accelerated corrosion test was run with t h e modified one just described. These tests were made by immersing t h e 5 samples above described in 20 per cent sulfuric acid continuously for 54 minutes. Table IVC gives t h e results of t h e test which was repeated with t h e same set of samples. TABLEIVC-STANDARDACIDACCELERATED CORROSION TESTS WEIGHT IN GRAMS Before Grams Loss CORROSION Sample Im; After immersion in weight per sq. cm. per hr. N o. mersion 1st 2nd 1st 2nd 1st 2nd 34175 8.3273 8.3235 8.3199 0,0038 0.0036 0.00053 0,00052 34185 7.8608 7.8569 7.8532 0.0039 0.0037 0.00055 0.00053 34196 6.7584 6.7557 6.7530 0,0027 0.0027 0.00040 0,00040 34204 6 6440 6.6406 6.6374 0.0034 0.0032 0,00051 0 00050 44009 5:3514 5.3498 5.3483 0,0016 0.0015 0.00026 0:00024
T h e t w o tests agree with one another and show t h e order of passivity of t h e alloys t o be as follows: 44009; 34196; 34204; 3417.5; 34185.
coNcLusIow-If these accelerated corrosion tests could be relied upon as accurately reproducing atmospheric conditions, i t would be clear t h a t t h e , addition of monel metal t o American Ingot Iron t o t h e extent of about I per cent produces a more non-corrosive alloy for sheet roofing materials t h a n t h e addition of similar small percentages of cobalt. This type of corrosion test shows t h e alloy containing 0 . 0 6 per cent Co t o be more non-corrosive t h a n
sheet of standard American Ingot Iron for comparison. These sheets were 30 in. b y 96 in. in dimensions a n d No. 26 gauge (0.0188 in. in thickness). All of t h e sheets were received in duplicate a n d analyzed as follows : American Ingot Iron 34175 S 0.026 P 0,009 0.010 M u 0.022 C u 0.016
c
1 per cent
Co Alloy 34185 S 0.034 P 0.006
c
0.015
M u 0.017 C u 0.028 Co 1.18
1 per cent 0.60per cent 0.35 per cent Monel Metal Co Alloy Co Alloy 34204 44009 34196 S 0.022 S 0.025 S 0.040 P 0.009 P 0.008 P 0.008 c 0.010 c 0.010 c 0.010 M n 0,020 M n 0.015 Mn 0.020 C u 0.020 C u 0.24 C u 0.024 Co 0.35 Ni 0.75 Co 0 . 6 0
T h e five sheets were mounted side b y side on a wooden frame built t o support them. They were exposed in a plane making 60" with a horizontal. They have been corroding since March 18, 1914, a n d since t h a t time photographic a n d visual observations have been made a t regular intervals. It will take at least another year for these sheets t o corrode through t o destruction, before which time n o
, Feb., 1917
$ -i.-"-+p
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
h
0.75%
075%"
I
675%
final conclusions can be drawn. Up t o this time i t would appear, however, t h a t t h e loss of weight of t h e I per cent cobalt alloy a n d of t h e 0.60 per cent cobalt alloy was less t h a n t h a t of t h e others. Both of these have formed very hard, dense, tenacious, protective coatings. While there may be some doubt as t o which is t h e least corroded sheet of t h e three, t h e I per cent cobalt alloy, t h e 0.60 per cent cobalt alloy, or t h e I per cent monel metal alloy, there can be no doubt as t o t h e fact t h a t all of these three are far superior in noncorrosive action t o t h e sheet of pure American Ingot Iron, or t o t h e sheet containing 0.35 per cent cobalt alloy. The pure American Ingot Iron sheet is t h e most corroded t o date. T h e accompanying graphs were prepared for t h e purpose of visualizing t h e foregoing data. GENERAL CONCLUSIONS
I-The corrosion, or loss of weight in grams per sq. cm. of original surface per hour is a function of t h e length of exposure, being less for t h e longer exposures. This is t r u e because of t h e property of these alloys t o form a self-protecting layer or coating. 11-The graphs representing Series I and I1 show remarkable similarity of form. These series were for independent corrosions of t h e same set of samples. Therefore such irregularities as appear in general are probably due, not to uncertainties of measurement, b u t t o lack of control of t h e physical structure of t h e alloys in preparation. 111-The alloys formed b y t h e addition of small percentages of copper, nickel and cobalt (from 0 . 2 5 per cent t o 3 . 0 per cent) t o American Ingot Iron, are more resistant t o atmospheric corrosion t h a n t h e pure American Ingot Iron, from which t h e alloys were prepared.
I35
IV-Considering t h e d a t a fop alloys formed by adding various amounts of cobalt (from 0 . 2 5 per cent t o 3 . 0 per cent) t o American Ingot Iron, with very little, if any, carbon content, i t is apparent t h a t t h e corrosion is not a simple function of t h e percentage of cobalt content. I n general, t h e corrosion of t h e alloys formed by t h e addition of 3 per cent of cobalt t o American Ingot Iron is about 7 j per cent as great as t h a t of t h e alloys formed by t h e addition of 0.5 per cent of cobalt. V-Alloys formed by t h e addition of 0 .2 j per cent t o 3 . 0 per cent cobalt t o American Ingot Iron, with very little, if any, carbon content, are corroded in t h e atmosphere t o a n extent varying between 5 0 per cent a n d 7j per cent of t h a t of t h e pure American Ingot Iron f r o m which t h e alloys were prepared. VI-Conclusions (4) a n d (5) are approximately t r u e for t h e corresponding nickel alloys as for t h e cobalt alloys. There seems t o be very little choice between t h e use of nickel a n d cobalt t o form alloys with American Ingot Iron containing between 0 . 2 5 per cent and 3 . 0 per cent of t h e added metal for t h e prevention of corrosion. This is t r u e so far as t h e disc tests show, b u t with t h e exception noted in Conclusion VII. VII-As corrosion progresses, all of t h e alloys prepared form self-protective coatings of oxides. It is noticeable throughout t h a t the oxides formed by t h e cobalt are darker, denser, and more tenacious t h a n those formed by t h e other alloys. VIII-The preventive effect of t h e protective coating mentioned in Conclusion VI1 does not seem t o have worked greatly t o t h e advantage of cobalt alloys, in spite of its more satisfactory appearance, in t h e length of time t h a t t h e above experiments were allowed t o run. IX-In order t o establish finally t h e possible ultimate advantages of t h e cobalt alloy protective coating, as compared with t h e other sheets, all of t h e alloys should be allowed t o corrode t o destruction. The results of such tests, as discussed in t h e text above, will be published later. X-The addition of copper t o American Ingot Iron t o a n extent between 0 . 2 j per cent a n d 0 . 7 5 per cent seems t o be conducive t o reducing t h e corrosion of American Ingot Iron under atmospheric conditions. I t is difficult t o say whether or not t h e addition of copper in these amounts has a greater or lesser effect t h a n t h e corresponding amounts of nickel or cobalt. Additional experiments will be required t o determine these facts, but there can be b u t little doubt t h a t t h e addition of copper, as above reported, diminishes t h e corrosion of t h e pure American Ingot Iron. XI-The amount of corrosion varies with t h e percentage of carbon in the alloy, as would be expected, and as may be seen best by reference t o t h e graphs. During t h e course of making t h e large number of observations set forth in this paper, which extended over a period of several years, t h e authors were from time t o time assisted b y Mr. C. H. Harper, Research Laboratory, Queens University, Kingston, Ont., now Professor, Moosejaw College, Saskatchewan; a n d Mr. Walter L. Savell, Research Laboratory, Queens
4 S D E-VGISEERI-VG C H E M I S T R Y Vniversity, Kingston. Ontario. n o x Metals Department, Deloro Mining & Reduction Company, Deloro, Ontario. The authors wish hereby t o acknowledge their indebtedness t o these gentlemen, and as well t o l f r . R . C. Wilcox, Research Laboratory. Queens UnLrersity, Kingston. Ont., now analyst, The Exolon Company Thorold. Ontario. b y whom most of t h e analyses reported in this paper m-ere made. 156
SIXTH
STREET, CAXBRIDGE,hZ.455ACHUSETTS
NOTES UPON OIL TESTING B y ACGUSTUSH. GILL Receired October 21, 1916 I-A
T E S r F O R OILS B Y S A L T I N G - O U T T H E I R SOAPS
I t is a well known fact t o t h e commercial soap maker t h a t different soap stocks require varying amounts of salt for t h e “salting out” process. I t occurred t o t h e writer t h a t if this could be made quantitative, i t would form a n additional criterion by which t o judge of t h e purity or genuineness of a n oil. Reference t o t h e literature revealed t h e fact t h a t this principle h a d already been made use of by Carpenter’ for detecting t h e presence of cocoanut and palm oils in soaps. Soap from ordinary oils requires from 8 t o I O cc. of a saturated solution of salt, whereas t h a t from cocoanut oil may require jo cc. The procedure is as follows: 2 g. of t h e oil are saponified with j cc. of I O per cent caustic soda, adding alcohol if necessary. Evaporate t o dryness on a water bath. dissolve t h e soap in warm water, cool, neutralize with hydrochloric acid. using phenolphthalein as a n indicator, a n d make up t o jo C C . Titrate I O cc. of this solution with salt solution ( 3 2 0 g. t o t h e liter) in a bottle after t h e manner of t h e determination of hardness in water until the lather obtained just does not persist for five minutes. From t h e HC1 used, and this titration with salt, calculate t h e grams of salt necessary t o precipitate t h e soap found from I g. of oil. The following results were obtained : T ~ B LI-GRAMS I~ NaCl P E R GRAMOIL Oil I I1 Pure olive . . . . . . . . . . . . . . . . . 2.2 2.1 11.6 Suspected sample Olive F o o t s ( ? ) , , , , , , , , . , . , , 1 0 . 6 Cottonseed.. . . . . . . . . . . . . . . 8 . 0 8.6 Linseed . . . . . . . . . . . . . . . . . . . 1 4 . 6 12.9 Oleomargarine.. . . . . . . . . . . . 2.8 2.8 1.4 1.2 Butter . . . . . . . . . . . . . . . . . . . Cocoanut., . . . . . . . . . . . . . . . . S o end point obtainable.
T h a t something was really wrong with t h e olive foots 11-as evident from t h e fact t h a t in making soap from
t h e m in a large way, i t h a d t o be “broken” twice a n d t h a t nearly double t h e usual quantity of salt was required. 11-.4
TEST FOR GELATIKOUS MATTER I N L I S S E E D OILS
I n determining unsaponifiable matter in linseed oil, it was noticed t h a t a white, cotton-like-looking cloud formed between t h e soap solution and t h e supernatant layer of gasoline. It was further noticed t h a t t h e oils which showed t h e greatest amount of this cloud or sludge were slowest in drying a n d gave t h e roughest, 1 W. L a n t Carpenter, Allen’s “Commercial (1910), 436
Organic Analysis,”
2
Yol. 9. S o .
2
dullest and least elastic surfaces. particularly in patent leather finishes. The procedure is as follows: Saponify I O g of the oil with 2 0 cc. I O per cent caustic soda, by heating in a 6 in. porcelain dish over a low flame. .idd x a r m water when necessary and boil until saponification is complete. Make up t h e soap solution t o 2 2 5 cc. in a graduate with warm distilled mater. Warm water should be used t o prevent t h e hydrolysis of the soap. Pour out 2 5 cc. into a 6 in. test tube, seven-eighths t o one inch in diameter, add 8 cc. of 8 6 ” gasoline (from Pennsylvania crude) and shake thoroughly. Whirl in a centrifuge a t 1800 r. p. m. for 3 min. by t h e watch a n d observe t h e amount of sludge t h a t forms between t h e layers. Ordinary linseed oil gives a sludge nearly I O nim. in thickness or more, while a n artist’s oil which had been thoroughly washed with water and allowed t o stand a n d settle gaye less t h a n j mm. which is t h e smallest amount ever seen in a linseed oil. The first linseed oil, on applying t h e “breaking“ test, “broke” a t about 2 9 j 0 C., while t h e artist’s oil did not “break” below 300’ C. Attempts t o remove all t h e sludge by centrifuging repeatedly ( u p t o nine times in one instance) with fresh gasoline were unsuccessful. More sludge was found in t h e ninth t h a n in t h e first centrifuging. The first time, however, gives comparative results. Xttempts t o make t h e test quantitative b y collecting and weighing on a tared filter were also unsuccessful. I~ASSACHCSETTS INSTITUTE OF TECHXOLOGY, CAMBRIDGE
COLOR TESTS FOR OILS-PALM
OIL
. B y AUGUSTUSH. GILL Received October 21, 1916
The chemist uninitiated in this subject would infer t h a t color tests for different oils rest upon t h e same firm basis as those for copper, iron or chromiumparticularly after hearing testimony in certain legal cases. Palm oil is positiT7ely sworn t o - n o t something giving reactions like palm oil-and this. on t h e strength of a single reaction lasting less t h a n t e n seconds! Speaking from a n experience of over thirty years, and from extensive a n d careful reading, this is not t h e case-color tests are merely circumstantial evidence. If a color test be obtained, there is a p r o b a b i l i t y t h a t a certain oil is present, b u t no certairtty. Xor can any positive conclusions be drawn from any one test, save t h a t of isolating unsaponifiable oil; one must have t h e evidence of several different tests, each confirming t h e other. Nor can any other conclusion be possible. The oils are products of organic life, and this is dependent upon conditions of growth, in t h e case of a vegetable oil, as t o whether t h e season be wet or dry, warm or cold, t h e fruit be underripe, fully ripe or overripe; and in t h e case of a n animal oil, upon t h e feed. A hog fed on corn gives lard of a higher titer test and lower iodine value t h a n one fed on mast. Similarly, cows fed upon cotton or sesame cake give milk, the fat of which responds t o t h e same color tests as do
