W h e r e UTM O ST RESISTANCE to th e a c tio n of s tro n g chem icals is re q u ire d , " N a tio n a l” c a rb o n a n d g r a p h ite a n d " K a rb a te ” p ro d u c ts excel. T h is m eans fo r h eaters an d h e a t exchangers. F o r p ip e , tubes, fittin g s, p u m p s, valves. F o r tan k s, ta n k lin in g s a n d fu rn ace lin in g s.
F o r flo o rin g a n d p o ro u s p ro d u cts. F o r in n u m e ra b le o th e r a p p lic a tions.
In m an y o f these, " K a rb a te ” m a te ria l is used. " K a rb a te ” e q u ip m e n t, in a d d itio n to b e in g im p erv io u s to seepage o f fluids u n d e r pressure, has a d ju sta b le p ro p e rtie s, ac c o rd in g to w h e th e r c a rb o n o r g ra p h ite is th e base. Specifically, th e p ro p e rtie s o f carb o n , g ra p h ite o r " K a rb a te ” p ro d u c ts can be p re sc rib e d fo r y o u r p a rtic u la r re qu ire m en ts.
" N a tio n a l” carb o n , g ra p h ite , an d " K a rb a te ” sp ecialty p ro d u cts and s tru c tu ra l shapes to d ay solve in d u s tria l p ro b le m s because no o th e r m a te ria l m atches th e ir u n iq u e ly com bined physical, chem ical, and e lectrical p ro p e rtie s.
Corrosion Resistant Contam inai!*No
High or Low Heat Transfer
B A R O F W H A T ? C a r b o n , G r a p h i te , o r
"K arb a te ” m aterial . . . o f course!
R e s is ta n t T h e rm al Shock
E a s y to F a b ric a te
E lectrical C o n ductiv ity
Ho Deformation o lH^H Temperature
N o t W<
fAolten
Keep Your Eye
onthe In fa n try . . . The Doughboy Does It!
The registered trade-marks "National” and "Karbate”
distinguish products of National Carbon Company, Inc.
N A T I O N A L C A R B O N C O M P A N Y ,
Unit of Union Carbide and Carbon Corporation
EBB
G eneral Offices: 30 East 42nd Street, N ew York 17, N . Y.
Division Sales Offices: Atlanta, Chicago, Dallas, Kansas City, New York, Pittsburgh, San Francisco
January 1. 1945 209
C A S T I N G
Duplexing Process M akes More Progress in M alleable Field
M. F. Becker, vice
ceived, through the melting, annealing, and cleaning departments to the shipping floor.
“The biggest development of the past year in the malleable industry has been the expansion of the duplexing process for producing malleable castings. This process utilizes a cupola (a vertical shaft furnace which is highly efficient) for melting the raw materials and refining and superheating the metal in pulverized coal-fired air furnaces. Foundries also have begun to use equipment for reduc
Bell-Type Radiant Tube Covers More A ccessib le for H eavy Job
troduction of the rectangular bell-type radiant tube annealing covers, similar to those used in the annealing of sheet and strip steel.
“Heavy truck castings weighing from 60 to 360 pounds, such as banjo and carrier housings, are loaded on a refrac
tory base. A 23-ton cover which carries the radiant tubes and combustion equip
ment is lowered over the white iron cast proportion throughout the entire heat treating cycle. gas and the temperatures controlled au
tomatically by recording controllers. One thermocouple is placed near the radiant tubes to prevent overheating of the al
loy tubes, and two thermocouples are located on the outside and inside of the charge. Temperature differentials are within 10 degrees throughout the charge.
The quality of malleable iron is on a par with that produced by any of the best furnaces in the industry.”
C ontinuously C harged C upola handling equipment and mold conveyors which require a continuous molten metal might be somewhat variable batches, any necessary correction of composition, and
superheating are accomplished. Mono
rail systems facilitate pouring.
“For annealing, some additional con
tinuous ovens have been installed but
tageous to install conveyorized molding, sand handling or duplex melting equip
ment. Many of these have, however, introduced further efficiency into their handling methods by the use of lift or other industrial trucks, for handling fur
nace charges, handling sand and castings
leable Founders’ Society has established its laboratory in Cleveland. There, the work of the well aualified technical or
ganizations of member companies is sup
plemented. Shop-practice engineers make regular field visits to the plants, sending in specimens for test and metal
lurgical examination. As an aid to all interested in malleable iron, ‘American Malleable Iron—A Handbook,’ first hand
book on this subject, was announced by the Society, in December.”
Better Comm and of Stress Distribution To Be Helpful
Oliver Smalley, presi
power shortage. That the progressive strides forward should be as numerous and fruitful as they have been is a trib
ute to both labor and management, and serves to point the way to a future brighter in many respects.
“The past year has emphasized one graduate. Foundry apprentice activity is unhappily small and the industry and its various associations should formulate and support programs designed to promote growth on a sound basis.
Continuously E ases Labor
270 / T E E L
C A S T I N G
“On the brighter side, changes in en
gineering attitudes toward iron castings and their applications have been fre responsibilities involve the selection of materials and product design. The mem
bership of the Institute has been par
ticularly active along these lines, corre
lating and making available service rec
ords and performance data as compiled by over 100 licensed foundries here and abroad.
“Paralleling increased study and under
standing of methods providing quality control in manufacture, have been equally important researches in the behavior of castings under the varied conditions im
posed upon them. Perhaps one of the most important was concerned with cast
ing designs which will allow a proper dis available for other uses through success
ful application of Meehanite castings.”
D esirable Characteristics Attained with Permanent Mold
Edward C. Hoenicke, dense, homogeneous structure without porosity, and free-machining characteris
tics are desired.
“Metallurgical developments—particu
larly in the field of alloys to increase mold life, better machine design for opening, closing, and cooling the molds, together with improved mold coatings and a better understanding of the quick cooling characteristics of gray iron poured in permanent molds—portends better production and improved physical and mechanical properties.
“The quality of permanent mold gray iron castings has been graphically dem
onstrated during the war due to their ability to replace many brass and bronze forgings and castings for which no ma
terial was available due to limitation or
ders. They can be used with distinct advantage in industries producing diesel engines, automobiles, trucks, tractors, refrigerators, washing machines, air con
ditioning units, valves, hydraulic controls, and many other products.
“New developments for ordnance pur
poses together with new fields opened up Sand Temperatures Key Factors
H. A. Schwartz, man temperatures reached by molding sand.
Up to quite recent times the foundry- American Foundrymen’s Association, the principles of heat transfer which govern what should be done are now receiving systematic attention. This trend may well ultimately make a science out of what was previously only a craft.
“A second problem, more metallurgi
cal in character, is that it is now being found necessary to study the grapliitizing reaction even in rather low carbon steels, since graphite formation has been found of commercial importance in super-heated steam lines where temperatures are main
tained over many years. This prob
lem is being energetically studied, but no complete clarification has as yet been reached.”
A vailability of Inoculants To E ase Problems of Control and processing treatments, insuring more certain repetitive results. That stand
ards could be raised in spite of diffi
culties in securing exactly the type of raw
materials, particularly scrap to which the producer has been accustomed, is a to study their possibilities.”
Centrifugal Casting of Cylinder S le ev es Seriously Considered
Garnet P. Phillips, unit for the mass of gray iron. Electric arc furnaces have found their place as the melting units to produce lower carbon and the higher alloy irons.
“Hot blast equipment for cupolas in foundries with sufficient tonnage to jus
tify the investment involved continue to and various physical properties. This practice, along with judicious alloying, tends to simplify melting problems as one base iron can be made to serve for a variety of types of castings.
“Laboratory control of molding and core sand properties, both at room and elevated temperatures, is being increas
ingly applied. There is a better under
standing of properties needed and a con
tinuing improvement in the control of these properties. The use of core blow
ing equipment continues to increase with more accurately made cores and increased production resulting.
"Centrifugal casting of cylinder sleeves and liners has received serious consid
eration and some increased application.
Large scale application will depend on whether superior properties can be de
veloped and lower overall production costs obtained as compared to the best static sand casting methods. Both of these factors remain to be demonstrated.
“There has been increasing applica
tion of stress relief heat treatment for dimensional stability and annealing where both stress relief and increased machin- ability are needed. Considerable experi
mental work is being done on hot quenching heat treatments arid harden- ability properties of gray irons.
“The future of the automotive gray
January 1. 1945 271