---few .••••«.'i
Alloy and Special Steels
O U L P H I T E - t r e a t e d a llo y a n d s p e c ia l s te e ls , w h ic h w e O h a v e p r o d u c e d f o r a n u m b e r o f y e a rs , h a v e s o lv e d m a n y p r o b le m s f o r s te e l u s e rs . T h e y h a v e b e e n m o s t s a tis fa c to r ily a p p lie d w h e r e m a c h in a b ility is o f firs t im p o r ta n c e . S u lp h ite tr e a t m e n t c a n b e a p p l i e d to m o s t ty p e s o f s te e l. I t h a s b e e n u s e d su c c e ssfu lly in th e p r o d u c tio n o f s h e lls , c r a n k s h a f ts , c a m s h a fts , a x le s , a n d g e a r s .
I f y o u b e lie v e t h a t y o u r c o m p a n y m a y h a v e a n a p p l i c a tio n f o r s u lp h ite - tr e a te d s te e ls , o u r s a le s a n d m e t a l l u r g ic a l staffs a r e a t y o u r se rv ic e . W e h a v e a c c o m p lis h e d s a tis fa c to ry r e s u lts f o r o th e r s a n d a re r e a d y to s e rv e y o u in th e s a m e w a y .
WISCONSIN STEEL COMPANY
A f f i l i a t e o f In t e r n a t i o n a l H a r v e s t e r C o m p a n y
G e n e r a l O f f ic e s : 1 8 0 N o r t h M i c h i g a n A v e n u e , C h i c a g o 1, I l l i n o i s
lanuary 8, 1945
117
now is inverted with the fluxed side touch some warping, therefore, weights are employed to keep all three plates to deadweight is evenly distributed across top of carbon strip. time material entered maximum heating chamber and before reaching cooling chamber. A standard hydrogen brazing furnace of the belt conveyor type was and cupronickel; blistering occurred only when too many impurities were present between plates, or when too much cop
per binder was used. The other devel
opment was the creation of gases during furnace brazing, caused by excessive ap
plication of flux. It was claimed dark soot developed at the start, affecting hy
drogen control. This was minimized by more careful distribution of flux.
Many samples were tested to deter
mine correct proportions in use of cop
per as the bonding medium. Accom
panying table shows approximate thick
nesses for each of the three components going into a super-clad product based on steel plate sizes from 1/16 to %-inch.
Thickness of copper should be at a minimum, pilot tests indicating 0.006- inch as average for lighter gages of steel and cupronickel. However, as shown by table, copper thickness was reduced to 0.0015-0.002-inch when combined as
bond with 1 / 16-inch thick steel and 0.020-inch thick cupronickel. Views in Figs. 4 and 5 at high magnification show illustrated were kept until completion of the piece. Hardness of tire mild steel section"' averaged—60 -rockwell B before brazing, while cupronickel plates av
eraged 44 rockwell B. After brazing, some occasions, blisters or bubbles would develop on the steel surface of the lower side. Remedial action to correct this trouble and other unsatisfactory condi
tions has been set forth previously.
Production Factors: In straightening these plates after warping occurs, a set of power rolls or hydraulic arbor press can be employed. Type of operation generally depends upon thickness of plate and am ount of distortion. After straightening, the plates for the header are sheared, or in some cases cut on a Do-All machine, to the required size.
Shearing and machining of material should be arranged so that if rough burrs are left, they should be on the steel side.
Under a production setup it was found that machining speeds and feeds could be increased when cupronickel material was at minimum thickness and steel at operations. Lightness of plates also con
tributes to machinability.
the requirem ents of most materials handling problems
118 / ■ T E E L
in g e n u o u s fello w , the d e sig n e r o f this g e a r la p p in g m achine.
Fully alert to the w id e d iversity o f the M a s t e r line, he h a s b een a b le to select units w h ich com b in e to g iv e him e x a ctly the
“d o u b le feature” action he needs.
This p o w e r drive incorporates a m e c h a n ica l v a ria b le sp e e d unit a n d a sta g e o f g e a r reduction on the righ t h a n d e n d to p ro vid e v a ria b le spe e d s, in e x a ctly the right ra n ge , fo r the sp in d le drive.
O n the other end is a righ t a n g le w o rm g e a r drive that p ro vid e s o sc illa tin g m otion fo r the la p p in g tab le. A ll o f these . , . the motor, the v a ria b le sp e e d drive, the tw o g e a r reductions . . . a ll are s ta n d a rd M a ste r units, that e a s ily com b in e info o n e cornetict, integral, p o w e r p a c k a g e . S a v e s o rd e rin g a n d m o u n tin g tim e . . . sa v e s sp ace . . . sa v e s m oney.
P ro b a b ly you w ill not need exactly the sa m e co m b in atio n o f m otor features illustrated b e lo w , but the M a s t e r line inclu des m otors for every current specification , every type o f enclosure, a n d every type o f m o u n tin g a rra n g e m e n t . . . in fact, is the m o st flexible, the m o st versatile line of m otor drives in the w orld.
In v e stig a te M a s t e r ’s u n u su a l a b ility to serve y o u e co n o m ica lly w ith m otors that re a lly fit the job in size s from 1 /1 0 to TOO HP.
T H E M A S T E R E L E C T R I C C O M P A N Y • D A Y T O N I, O H I O
Above— Heating coils and fixtures of various design, each for a specific
job, are readily available Below— Repetitive localized heat treating with induction unit. Heat
ing is so rapid that parts may be removed by hand for quenching.
Part is inside small coil in front of board above quench tank
S h o p jp ^ i
By REX BAUBIE, Chief
In d uction H e a t in g D ivisio n C e n tra l B o ile r & M f g . C o.
Detroit
ECONOM IC factors involved in the practice of heat treating metals by appli
cation of electronically induced high- frequency current have given rise to an entirely new service in the metalworking industries—the induction heat treating job shop.
Induction heat treating as a job shop operation rather than a departm ental function within a plant is a logical devel
opment created by wider acceptance of induction heat treating itself. It is justi
fied economically if consideration is given cost of installing the necessary equip
ment, training the personnel to operate it and m aintaining that personnel through the idle periods bound to occur from tim e to time within a large industrial plant.
In the case of small plants or other job shops the economic value of “farm
ing out” such work to a specializing shop is even more pronounced because of (1 ) high cost of the equipment, (2) the limited use it would have, (3 ) the trained technicians its operation requires and (4 ) the per-unit cost of work turned out.
The job shop having an induction heat
ing departm ent, experienced in that high
ly specialized type of operation and fully equipped to handle any induction heat treating operation, need not suffer from such economic prohibitions.
Assuming its business is sufficient to keep its equipm ent in operation most of the time, costs can be spread over numer
ous projects, thus lowering the cost per- unit to a figure an owner using the equip
m ent only occasionally cannot hope to attain. Furthermore— and this is import
ant— the induction heat treating job shop can supplement its lower per-unit cost
with the counsel and services of electronic and metallurgical engineers of a caliber few occasional users of the process could afford to maintain.
The nature of induction heat treating makes it adaptable to projects of widely different requirem ents as to size, shape and length of run. That, fortunately, is inherent in an electronic induction cir
cuit. Fortunately the more costly ele
ments of the apparatus transformers, rec
tifiers and oscillators— remain more or less standard for all types of heat treating jobs. The fixture which actually ap
plies energy to the work being treated, the coil, is not only the least expensive part of the equipment but is both de
tachable and interchangeable. It is in reality an attachm ent but is of course as necessary to operation of the unit as a drill bit is to a drill press.
High frequencies necessary to heat treat inductively are generated by the more expensive elements of the equip
m ent and delivered to output terminals.
The coil is attached to the terminals sim
ply by plugging in. Removal of one coil, substitution of anolher is no problem.
Induction heat treating coils, however, must be designed to m eet specific re
quirem ents of a given job. Adequate coverage of the area to be treated and proper clearance from the work are two of the more im portant factors in coil de
sign. It also is im portant to know what frequency to use as well as exactly how long to expose the work to th at frequency.
Those are problems for the induction heating engineer.
Through the interchangeability of coils, induction heat treating is adaptable to an
( Please turn to Page 136)
120 / • T E E L