INDUSTRIAL AND ENGINEERING CHEMISTRY Hall, F. A4., Sheet Metal Indd., 30, 790--9 (September 1953). Grodner, A., Indiistl'y a n d W e l d i n g , 26, 54-5 (May 1953). Halbig, J . J., and associates. I r o n Age, 172, 159-63 (December 10, 1953). I n d u s t r y a n d Welding.26, 53, 54, S2 (Xovember 1953). Iieating, F. H., Weldel., 22, 61-9 (April-June 1953). Linwrt, G. E., and Larrimore. R.J I . , Materials R. Methods, 38, 98-103 (November 1953). Xetal W o r k i n g , 9, 20-1 (October 1953). Patriarca, P., and Slaughter. G. XI.. W e l d i n g J.. 32, 597--602 (July 1953). Pilia, F.J., I b i d . , 32, I167 -1174 (December 1953). Pooie, L. K., Ibid., 32, 4038-128 (August 1953). I b i d . , 32, 1160-6 (December 1953). Riordsn, J. PI., Samuelson, D. O., Ibid..32, 603--11 (July 1953). So!o!non, R. E., Iron Age, 172, 142-4 (December 10, 1953). Spencer, L. F., W e l d i n g Engv.. 38, 45-9 (June 1953). I b i d , 2 42-6, 48 (November 1953). Steel Horizons, 15, 24, 4th Quarter (1'36.7). Thieisch, H., Materials & Methods, 37, 115-30 (May 1953). Tremlett, H. F., W e l d i n g , 21, 136--44 (April 1953). Viies, P. S., (to Standard Oil Deveiopinent Co.), U. S. Patent 2,638,665 (May 19, 1953). Warburton-Brown, D., Weld./7Lg u n d Metal Fabrication, 21, 239-41 (July 1953); 291-5 (August 1953). Weinatein, M. S., Maciiinist, 97, 1653-5 (October 3. 1953). Wooding, W. H., W e l d i n g ,I.. 32,299-312 (-1pril 1953); 407-23 ( 3 I a y 1963). GESERA L
Alien. L. >I., and Woodard. TI., Steel Processing, 38, 615-20 (December 1952). e l , 134, 92-5 (IIarch 22. 1954); 106-8 Batta., G., Scheopers, L., Winandy. L.. and Dallemange, G., Reo. met., 50, 49-56 (January 1953). Batten, W. L.. Steel, 133, 78-81 (December 1, 1953). Erisssy, R. &I., and Chase, G . A. Am. M a c h i n i s t , 97, 132-3 (dpril27, 1953). Chariesworth, P. A., and Hobson, C., Sheet Metal I n d s . , 30, 825-32, 834, 837, 841 (September 1953). Cope, 9. R.. Am. Macitinist, 97, 110-3 (August 3, 1953). Daurat, J., Mbtallurgie, 85, 885, 887 (Kovember 1953). Deac. A. G., Engineer, 195,853-5, S82-4 (June 19 and June 26, 1953). Dunn, R. H., and Day, li. E., Product E n g . , 24, 129-33 (September 1953). Electroplating a n d Metal Sp,.uy.lng. 6, 267, 209-71 (July 1953). Greenwood. H. W,, Metel Treatment a n d Drop Forging, 20, 427-9, 431 (September 1953). Holden, H. X., Sheet M e t a l Inds., 30, 7i5-8, 819 (September 1 Q.53)
Holnistrom, C. E., Ibid., 30, 706-7 (September 1953). Hunt, L. J., Ibid., 30, 779-80, 783. Iierlss, 1%'. F. G., Wzre I d . , 20, 1095-6, 1099-1100, 1103, 110%.1113 (Soveniber 1953) Langhammer, A. J., and Click, P , Product Eng., 24, 179-82 (April 1952).
Vol. 46, No. 10
( B E ) Lloyd, 11. H., Sheet Metal I n d s . . 30, 767-74, 784 (Septernhr 1953). (1SE) Lomas. J., M a c h i n e r y Lloyd (Overseas Ed.), 25, 82--3 (Yeptciiiber 26, 1953). (20E) Materials & Methods, 38, 116-8 (October 1953). (21E) Metal Ind. ( L o n d o n ) , 82, 329 (April 24, 1953). (22E) Mott, S . 3. (to Cooper Alloy Foundry), U. S. Patent 2,635,044 (April 14, 1953). (23C) Paret, 1%.E., Materials & Methods, 38, 98-101 (Decenilxr 1953). ( 2 4 E Post, C. E., and Beaver. H. O., Blast F u m a c e Steel P i a n ! , 41, 627-34. 645 (June 1953). (253) llassbach, H. P., and Saunders, E. R., J . Metals, 5 ( h u g w t 1953). (26E) Seelig, R. P., Materials & Methods, 37, 106-9 (May 19 (27E) Sheet Metal I n d s . , 30, 785-6, 798, 799 (September 195 (283) Ibid., p. 906. (29E) Shortsleeve, F. J., and Nicholson, 11. E. (to Standard Oil C'i, of Indiana), U. S.Patent 2,671,050 (March 2, 1954). (30E) Smith, E.. Sheet Metal I n d s . , 30, i63-6, 820 (September 1 (31E) Spencer, L. F., I n d . Heating, 20, 220-2, 224 (February 678, 680, 682, 684, 686, 688, 690 (.lpril 1953); 879--88 881 (May 1953). (32E.j Spencer, L. F., Metal F i n i s h i n g , 52, 54-9 (February 1954). (33E) Steel, 133, 82-3 (August 24, 1953). (34E) Steel Horizons, 15, No. 2, 12-3 (1953).
(35E) Ibid.. pp. 24-5. (36E) Steel ProcessiGg, 39, 324-6 (July 1953). (37E) Stevens, G. J., M a c h i n e r y , 6 0 , 196-200, (December 1953j. (38E) Stiles, F. J., Sheet Metal I n d s . , 30, 800-3 (September 153). (39E) Tancryn, H. (to Armco Steel Corp.), U. S. Patent 2,614,921 (July 21, 1953). (40E) Too2 Engineer, 31, 81-4 (December 1953.) (41E) Von Ludwig, D., Metal Progr., 63, 84-7 (April 1953). (4%) Warga, F., F o u n d r y , 82, 124-7 (April 1954). (43E) Wilson, L. H., Steel, 133, 96-8 (August 10, 1953). (44E) Zapffe, C. A., Metal Progr., 64, 88-90 (December 19531. (45E) Ziegler, S . A. and associates (to Crane Co.), U. S. Patent 2,616,798. MISCELLANEOUS IRON BASE ALLOYS
(IF) dgladze, R. I., and Gdzelishvili, >I. Y . , Soobshcheniua Akuti. Kauk. CruzinskoZ S.S.R., 10, 615-20 (1949). (2F) Allen, N. P., and associates, J . I r o n Steel Ins!., 174, 105--20 (June 1953). (3F) Ramforth, 4.W., T h e Times Ret. of Ind.,7, 28-9 (May 1953). (4Fj Cech, It. E.. and Hollomon, J. H., J . Metals, 5, Sect. 2 (May
1953). (5F) Denison, I. A., and Romanoff. XI., J . Reseurch :Vat. [ ~ I I J . Standards, 51, 313-20 (December 1953). (6F) Erikson, S.,Svetsaren, 17, 30.2. 15-20 (1952). (7F) Fitzer, E., 2. Metallkunde, 44, 462-72 (October 1953). (8F) Luce, W.A, Cheni. Eng., 61, 246, 8, 250, 2 , 4, 6 , 8,26:) (Jaiiuary 1951). (9F) Sefing, F. G. (to International Kioke! Co.. Inc.), C. 8. Patent 2,646,375 (July 21, 1953). (10F) Srikantiah, B. S., and Parthasarathi, M . K.,J . Sci. I n d . R e search ( I n d i a ) . 10B, 322--4 (1951). (11F) Stearley, G. H aterials & Methods, 37, 115-30 (Aprii 1953),
i
nd Its Alloys -
ROBERT J. NEKERVIS Tin Research I n s t i t w e , l n c . , Columbus 1: Ohio
I n keeping with the new- INJIUSTRIAL AND ENGINEERIKG CHEMISTRY policy on the Materials of Construction Review, this review will cover only the more important developnieraks relating to tin.
3. Tin soon would not lw rogartletl as a critical war material because of known alternative materials.
I
K 1,lYT year's review, reference was made to the President's
hlaterials Policy Commission finding that' the specter of short supply m-ould not frighten the tin consumer, because 1. T h e availability of tin for the next 25 years mas good, as was the expectation of future discoveries. 2 , The projected increase in demand in the next 25 years was iow-of the order of 25% over the 1950 base period.
The Commission findings on the nickel situation mere not S O good, particularly regarding increase in demand and availability. -4lthough the past year has seen a n easing in the nickel supply situation, the long term situation is practically the same as that reported by the commission. Accordingly, work has been directed toward the replacement of nickel-by tin in electrocoat-
October 1954
INDUSTRIAL A N D E N G INEERING C H E M I S T R Y
2125
ings arid in copper alloys. During the past year, considerable progress has been made in these fields. T I N AS A REPLACEMENT FOR NICKEL IN ELECTROCOATINGS AND COPPER ALLOYS
Tin-Bronze Alloy Electroplate. Chromium in decorative chromium plate serves only to keep the underlying protective metal from turning dull. These underlying protective met>alu, which in turn are used to protect steel and zinc die casting alloy arfaces, have been nickel and copper, for the most part, with enilhaais on the nickel. Copper alone as an undercoat for chromium has been inadequate. With nickel in short supply for the foreseeable future, a great' deal of development work is under way t,o find adequate undercoatings for chromium electroplate. Corrosion studies conducted since last year (39) indicate that tin-bronze is quite satisfactory, both as to performance and cost. Bright plating of tin-bronze has been developed on a commercial scale in the U. S. (14, 37-39) and elsewhere ( 4 1 , 6 5 ) . Comparative corrosion tests (39) of chromium plate on steel with undercoatings of bright tin-bronze from a cyanide-pyrophoephate bath show t.hat tin-bronze is superior to an equivalent thickness of bright, nickel undercoatings in salt spray tests and weather exposure tests at Daytona Beach, Fla. (Figure 1). I n Pittsburgh * afmospheres, buffed nickel had a slight edge over tin-bronze. However, with a flash of nickel over the tin-bronze, the tinbronze undercoats were superior. Tin-bronze undercoatings containing from 17 to 20% tin have the optimum combination of mechanical properties, brightness, and leveling power when deposited from a cyanide-pyrophosphate bath (39). The chemical engineer is int>erestedin tin-bronze electroplates as bearing surfaces in hydraulic pumps (58)as shown in Figure 2. Tin-bronze plating has been used to solve a number of design and corrosion problems (57,41). Tin-Nickel Alloy Electrocoatings. Only electrocoatings of tinnickel alloy, chromium, and the precious metals are nontarnishing. Tin-nickel alloy coating contains two thirds tin, one third nickel. While not a replacement for nickel, this alloy saves two thirds the nickel used in chromium-on-nickel coatings for equivalent protection. Recent comparat'ive tests show that tin-nickel alloy coatings maintain their brightness much better than chromium-onnickel coatings, both in indoor and outdoor exposures, and also on articles that are subject to handling ( 3 ) . As corrosion progresses, the deterioration in the appearance of each type of coating follows different patterns. The chromium-on-nickel coatings show a general loss of brightness; the t'in-nickel alloy coating shows dark spotting on a n otherwise bright surface. Yeither has a clear advantage under all conditione. The chromium-on-nickel coatings are superior in atmospheres near the sea. Although the tin-nickel alloy coatings retain their brightness better than the chromium-on-nickel coatings even in sea atmospheres, pore corrosion in the tin-nickel alloy coatings is more severe. I n the transfer of tin-nickel electroplating from pilot plant to commercial operation, several developments in technique improve both the appearance of the coating and the ease of operation of the chloride-fluoride bath. These developments include filtering the bath through paper rather than carbon to stop occasional pitting caused by traces of carbon entering the bath, reducing sludging by doubling the anode current density, and obtaining brighter coatings through better control of the bath conatituents, particularly the fluoride concentration ( 4 , 1 0 , 1 1 , 4 8 ) . Tin as a Replacement for Nickel in Copper Base Alloys. From the standpoint of conserving nickel, the new tin-nickel-copper alloys are an alternative to the established cupro-niche1 coining and &ing alloys. These cupro-nickel coining alloys must contain a t least 25% nickel to attain the proper white color. Replacing 40% of the nickel---is., 10% of the total alloy content-with 3 to 5% tin provides a conibination of hardness and color of the same order as that of the (75:25) oupro-nickel allog I n addition, the higher tin content, alloy containing 5% tin, 15%
Chromium plate with bright 20% Tin-hronse undercoating (0.0010-inch 20% tin-bronze 0.0002-inch bright nickel 4- 0.00001i n c h chromium)
+
Chromium plate with bright nickel undercoating
(0.0010- to 0.0012-inch bright nickel $. 0.00001-inch chromium)
Figure 1. Chromium Plated Steel Panels Exposed a t Daytona Beach, Fla., from January 1 to June 15, 1954 Show Tin-Bronze Undercoatings Are Superior t o Equivalent Nickel Undercoatings
nickel, balance copper possesses a distinct advantage over the binary cupro-nickel alloy, because it can he put in a soft condition for stamping and then hardened afterward by heat treatments (9). Copper-Manganese-Tin Alloys as a Replacement for NickelSilver. Copper-manganese-tin alloys in the range 4 to 14% tin, 15 to 20y0manganese, balance copper have been investigated ( 1 ) . Commercial development has concentrated on a 6% tin, 16% manganese, balance copper alloy. Manufacturers of tableware in England have found that this alloy is a successful replacement for nickel-silver in the manufacture of plated household equipment. The alloy is almost white, has good ductility, and can he easily polished, plated, and hand soldered. I n addition these replacements for nickel help to relieve the critical situation on nickel, and they provide sorely needed markets for tin. NEW TIN-CONTAINIhG MATERIALS
Organotin Compounds. Dibutyltin compounds as stabilizers for polyvinyl chloride plastics are now firmly established. The mechanism of stabilizer action and its effects on clarity, color, and other properties have been the subject of numerous studies (26, b7, 43-45). Tin ricinoleate has also been tried as a polyvinyl chloride stabilizer (19). Some trialkyltin and triaryltin compounds have the unusual merit of combining extremely powerful fungicidal and insecticidal properties. The value of these compounds as pesticides is now being assessed (61). New Tin-Containing Alloys. I n the field of metals, there are a number of developments that relate to tin; the first of these is the use of tin in titanium-aluminum alloys to increase strength without losing fabricability, thus making this alloy markedly superior to other interstitial alpha-type titanium alloys (15). Another quite different alloy is designed for use as a heat transfer
INDUSTRIAL AND E N G I N E E R I N G CHEMISTRY
2126
Vol. 46, No. 10
BASIC RESEARCH
Of the vast amount of basic research relating to tin reported during the past year, the following have been selected as most likely to have immediate practical value. 1. Factors affecting the transformation to gray tin at low temperatures (34,56). 2. Causes of growth of metal whiskers on electrotin coatings (16, 1 7 , 2 3 ) . 3. The zirconium-tin alloy system (25, 4 6 ) . 4. T h e effect of hydrogen on the embrittlenient of zirconiumtin alloys ( S I ) . 5. Titanium-tin alloy structures (66). 6. The copper-manganese-tin system (18). 7. The low temperature alloy systems-tin-bismuth-antimony (54)and tin-bismuth-lead ( 2 2 ) . 8. The liquid immiscibility region in the aluminum-lead-tin system (12). Y
.
Figure 2 Tin-Bronze Plated Cast Iron Housings and Caps for Vane-Type Pump Motors Provide Better and Cheaper Bearing Surface Than Do Solid Wear Plates
medium where a cadmium constituent in the alloy would be detrimental (42). This alloy which melts at 60’ C. contains 50 to 5 2 7 , indium, 31 to 33% lead, and 16 to 18% tin. New Glass Solder. A patent has been granted on a solder that is capable of vetting ceramics and providing a seal t h a t will withstand 25 pounds per square inch air pressure, and the expansion and contraction forces associated with alternate heating and cooling between 5’ and 140” F. ( 2 ) . The solder contains 707, tin, 1870lead, and 12% indium. New Soldering Methods. Zirconium, rvith its tenacious oxide coating, can not be soldered or brazed by regular methods. B y dipping it in molten zinc chloride at 825’ t o 8-10’ C. t o provide i t with a zinc coating, it can be readily soldered or brazed (40). This method does not work lvith titanium, but methods of soldering and brazing this equally reluctant metal have been published (36). Printed circuits are the key factor in the drive toward automation in the electrical and electronic industry (SO). Many different methods of printing and soldering circuits have been evolved (7,JO, 4 7 ) . New Bearing Alloy. A light alloy for bearings based on the aluminum-tin-titanium eystem has been announced. This alloy contains 6.3 to 6.6% tin, 0.8 t o 1.8% titanium, 1.0% copper, balance aluminum (8). UNUSUAL COATIXG RIETHODS
A patent has been issued on a method t o bond aluminum to steel t h a t involves hot galvanizing the steel article in a spelter containing 10% tin and 0.4% aluminum and then casting the aluminum alloy around the article before the coating freezes (33). Uethods of obtaining satisfactory tin coatings on aluminum by means of chemical displacement have been published (5, 6, 60, 6 5 ) along vit,h methods of immersion tinning other metals (34). CORROSION RESISTANCE OF T I h ARD TIN ALLOY COATIRGS
Corrosion resistance studies of the recently developed tin alloy electrocoatings are being continued (20, 49). The protection offered by the 807, tin-20% zinc electrocoating is superior to t h a t of cadmium in almost all conditions. Cadmium gives similar results only in pure marine conditions. Zinc coatings seem more resistant t o weathering. The advantage of this tin-zinc alloy coating is that i t can be directly painted, soft soldered, or spot welded. Steel pieces coated with it can be used in conjunction with aluminum without inducing corrosion couples (20). Protective chemical treatments for tin have been improved (21).
INFORMATION RELATING TO TIT O F PRACTICAL EWGIhEERING VALUE
There are several publications relating t o tin that are comprehensive in scope and provide up-to-date engineering data. The first of these is a revised edition of the Tin Research Institute publication “The Properties of Tin” ( I S ) . Properties of tin alloys have also been covered in a recent publication (28, 29). Current uses for tin are discussed in a revised AIME publication on modern uses for nonferrous metals ( 3 2 ) . The U. S. National Production Authority has published a materials survey on tin that cover8 all phases of the subject (62) LITERATURE CITED
W., J . I n s t . Metala, 82, 17--24 (September 1953) (2) Bolton, 11.J. (to General Electric Co.), U.9. Patent 2,636,820 (Ami1 28. 19531. (3) Brit&, S. C., and Angles. R. hl., Inslitute of Metal Fi,tishang, Bull. 3,259-80 (Kinter 1953). (4) Britton, S. C., and Michael. D. G., Ibid., 3, 143-62 (lutumn 1953). (5) Bryan, J. ?.I.. iVetuZInd. ( L o n d o n ) ,83, 461-3 (Dec. 4, 1953). ( 6 ) Ibid.,pp. 502-4 (Dee. 18, 1953). (7) Caffiaua, J., Hannahs, W., and Stein, N., Tele-Tech. 13, 65-70, 150-5 (February 19d4). (8) Collari, S . , and Paglialunga, L., Alluminio, 22, 22-7 (January 1953). (9) Cuthbertson, J. W., Metal Ind. ( L o n d o n ) , 82, 301-3 (April 17, (1) Blade, 3. C., and Cuthbertson, J.
1953).
(10) Ibzd.r83,89-91 (July31,1953). (11) Cuthhertson, J. W., Parkinson, K.,and Rooksby, H. P., J. Electrochem. SOC.,100, 10i-19 (LIarch 1953), (12) Davies, iLI. H., J . Inst. MetaZs, 81, 415-16 (April 1953). (13) Faulkner, C. J., “Properties of Tin,” Tin Research Inst., Green-
ford. Middlesex, England, March 1954. (14) Faust, C. L.. and Hespenheide, W. G. (to City Auto Stamping C o . ) , U. S.Patent 2,658,032 (Nov. 3, 1953). (15) Finlay, W.L.. and associates, J . Metals, 6, 25-9 (January 1954). (16) Fisher, R. M., Darken, L. S..and Carroll, B.G., Acta Metallurgica, 2,368-73 ( M a y 1954). (17) Frank, F. C., Phil. X a g . , 44,854-60 (August 1953). (18) Funk, C. IT., and Rowland, J. A,, Trans. Am. Inst. M i n i n g N e t . Engrs.. 197,1723-5 (1953). (19) Furter, F., Kz~mtatofe,43, 189-91 (May 1953). (20) Hedges. E. S.. Corros.lon et Bnticorrosion, 1, 88-93 (1953). (21) Hedges, E. S., Metaur (Corrosion-lnd.), 28, 171-4 (April 1963). (22) Ho, Teh-Hsuan, Hoffman, W., and Hanneman, H., Z . Metallk u n d e , 44, 127-9 (April 1953). (23) Koonce, S. E., and Arnold, S. M., J . A p p Z . Phys.. 24, 366-6 (1953). (24) Lowenheim, F. A., “Modem Electroplating,” pp. 429-34, John Wiley, New York, 1953. (25) NcPherson, D. J., and Hansen, XI., “Zirconium and Zirconium Alloys,” pp. 222-35; disc., pp. 239-340, American Society for Metals, Cleveland, 1953. (26) Mack, G. P.. Modern Plastics, 31, 150, 152, 154, 218-21, 223, 225-6 (November 1953). ( 2 7 ) Mack, G. P., E t t n s t s t o f e , 43, 94-101 (1953). (28) Materials & Methods, 37, 127 (March 1953). (29) I b i d . , p. 129.
October 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
(30) Modern Plastics, 31, 91-9, 217-18 (April 1954). (31) lludge, W. L., Jr., “Zirconium and Zirconium Alloys,” pp. 146-67, American Society for Metals, Cleveland, 1953. (32) Piekervis, R. J., and Gonser, B. W., “Modern Uses for Nonferrous Metals,” 2nd ed., Chapter 21, American Institute of Mining and I\.Ietallurgical Engineers, New York, 1953. (33) Pershing. W. H., McClain, J. J., and Fulwider. J. A. (to General Motors Corp.), U. S. Patent 2,634,469 (April 14. 1953). (34) Rogers, R. R., and Fydell, J. F., J . EZectTochem. SOC.,100, 161.~4 (April 1953). (35) Ibid., 383-7 (September 1953). (36) Rostoker, W., Light Metal Age, 11, 11, 26 (October 1953). (37) Safranek, W.H.. Hespenheide, W. G., and Faust, C. L., Metal Finishing, 52, 70-3, 78 (April 1954). (38) Safranek, W. H., Neill, W. J., and Seelbach, D. E., Steel, 133, 102-4, 106, 109 (Dee. 21, 1953). (39) Safranek, W. H., and Faust, C. L., “Copper-Tin A4110yPlating,” presented at the Annual AMeeting of the Am. Electroplaters’ Soc., Xew York, July 13,1954. (40) Schickner, W. G., Beach, J. G., and Faust, C. L., S f e e l , 132, 11819 ( ~ a y 41953). , (41) Schmerling, G., Metal Ind. (London),81, 87 (June 12, 1953).
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2127
(42) Smith, A. A,, Jr., and Everhart, J. L. (to Am. Smelt. & Refining Co.), U. S.Patent 2,649,368 (Aug. 18, 1953). (43) Smith, H. V., Product Finishing, 6,42-8 (June 1953). (44) Smith, H. V., Rubber Age and Sgnthetics, 3 4 , 2 0 6 7 (July 1953). (45) Smith, H. V., T i n and Its Uses, No. 29, 7-8 (1953). (46) Speich, G. R., and Kulin, S. A,, “Zirconium and Zirconium Alloys,” pp. 197-207, American Society for LIetals, Cleveland, 1953. (47) Stones, A. E., Tde-Tech, 12, 62-4, 160. 163 (December 1953). (48) T i n andZts Uses, No. 28, 10-11 (June 1953). (49) Ibid., No 29, 1-5 (September 1953). (50) Zbid., No. 30,8 (May 1954). (51) Tin Research Institute, “1953 Report of the Tin Research Institute,” pp. 18-19, Tin Research Institute, Greenford, Middlesex, England, 1954. (52) U. S.Dept. Commerce, National Production Authority, Washington 25, D. C., “Materials Survey Tin,” 1953. (53) Vaid J.. and Rama Char, T. L., Carrent Sei. (India),22, 170-1 (1953). (54) Vogel, R., 2. Metallkunda, 44,3234 (July 1953). (55) Wilson, J. K., and Wright, O., Aircraft Prod., 15, 329-34 (September 1953). (56) Worner, H. W., J . Inst. Metals, 81, 521-8 ( J u l i 1953).
-~ -
WOOD
ROY H. BAECHLER AND ALFRED J. STAMM, Forest Products Laboratory, Forest Service, U . S. Department of Agriculture, Madison 5, Wis.
This review covers developments in wood products during the period April 1951 to April 1954. Sections on mechanical properties and on fiberboards are not included in this year’s report.
T
q t several years have seen no dramatic changes in the general practices of the wood-treating industry. A number of trends are noticeable, however, and several new development3 may ultimatelv prove to be of great practical importance.
PRESERVATIVE AND PROTECTIVE TREATMENT
Statistics ( 7 7 ) show a 4% increase in the wood-treating industry during 1952 compared with 1951. Of the products treated, wood blocks showed an increase of 35% and fence posts an increase of 30%. Pentachlorophenol solutions showed the largeEt percentage increase among the oil-type preservatives, and Chemonite among the water-borne preservatives. The total consumption of coal tar creosote, including solutions of creosote and coal tar, was approximately 227,000,000 gallons, of which approximately 67,000,000 gallons were imported. About 12,500,000 pounds of solid preservatives were used, which included somewhat less than 2,000,000 pounds of file retardants. Of the newer preservatives, Boliden salts, celcure, Chemonite, copperized chromated zinc chloride, and Greensalt were adopted as standard preservatives by the American Wood-Preservers’ Association (8). A relatively large number of papers were published during the past several years concerning the chemical composition, effectiveness, and methods of testing coal tar creosote. Mayfield (60) reviewed studies of the toxic constituents of coal tar creosote. Roche (66) listed 162 compounds found in creosote and pointed out that toxic compounds are found thrpughout the boiling range. Baechler ( 7 ) showed that all of the distillation fractions of low temperature-tar creosote are toxic due to the presence of tar acids, which on aeration undergo only a small loss in toxicity. Heicks and coworkers (42,43) reported on infrared, solvent extraction, and othcr studies of 16 creosotes of various types and sources. They described an x-ray technique for identifoing aromatic hydrocarbons in creosote and also a method bascd on differential solubility in p,p’-oxydipropionitrite for detecting petroleum in creosote. Andrews ( 4 ) shoived that some, but not all,
high boiling hydrocarbons in creosote depress the volatility of low boiling hydrocarbons, such as naphthalene. Most papers on the newer preservatives concerned pentachlorophenol. Duncan and Richards ( 5 0 ) published favorable results 011 creosote-petroleum-pentachlorophenol solutions tested in the laboratory b y the soil-blcck method. Duncan (28) also reported varied degrees of effectiveness for oil-tar creosote with and without pentachlorophenol> and for lignite-tar creosote with and without tar acids removed. Sedaiak ( 7 2 ) gave favorable results by soil-block tests on solutions of pentachlorophenol and copper naphthenate. Snoke ( 7 4 ) , with similar tests, showed t h a t if pentachlorophenol is added to creosote, a n increase in effectiveness may be expected. Progress reports were published for service tests being made on a large number of preservative materials by railroads, utility companies, and public institutions. A number of committee reports of this type appear in the Proceedinps of the Smerican Wood-Preservers’ Association and the Proceedings of the American Railway Engineering Association. Lumsden (63) summarized the condition of posts and poles treated with many materials and exposed for 25 years in a test plot in Mississippi. Blew and coworkers reported the latest inspection results of stake tests ( 1 6 ) being conducted in several locations and post tests ( 1 6 ) being conducted in Mississippi. H u n t and Snyder ( 4 8 )presented a progress report on stakes treated in 1928 and exposed in termiteinfested areas in Australia, Hawaii. Panama Canal Zone. and South Africa. Richards (66) gave a progress report on panels treated with various types of creosote and blends with coal tar and petroleum and exposed to marine organisms in t u o coastal installations. Graham ( 5 9 ) reported on the latest inspection of treated and untreated posts in a plot maintained by the Oregon Forest Products Laboratory Several noteworthy publications on the pressure-treating process appeared in the literature, including a revision of XfacLean’s ( 5 7 ) comprehensive treatise. Hudson (45, 46) described a method for recovering organic solvents from wood pressuretreated with solutions of pentachlorophenol or copper naphthenate that effects economies and improves paintability.
