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Sulphur
Sulphur is another impurity and high sulphur is even a greate...

Corrosion
This steel like any other steel when distorted by cold worki...

Heating
Although it is possible to work steels cold, to an extent de...

Detrimental Elements
Sulphur and phosphorus are two elements known to be detrimen...

Take Time For Hardening
Uneven heating and poor quenching has caused loss of many ve...

Heat Treatment Of Gear Blanks
This section is based on a paper read before the American Gea...

Silicon
SILICON is a very widespread element (symbol Si), being an es...

High-carbon Machinery Steel
The carbon content of this steel is above 30 points and is ha...

Carbon Tool Steel
Heat to a bright red, about 1,500 to 1,550 deg.F. Do not ham...

Tool Or Crucible Steel
Crucible steel can be annealed either in muffled furnace or b...

The Penetration Of Carbon
Carburized mild steel is used to a great extent in the manufa...

Hardening High-speed Steel
In forging use coke for fuel in the forge. Heat steel slowly ...

Knowing What Takes Place
How are we to know if we have given a piece of steel the ver...

Lathe And Planer Tools
TO FORGE.--Gently warm the steel to remove any chill is parti...

The Influence Of Size
The size of the piece influences the physical properties obta...

Short Method Of Treatment
In the new method, the packed pots are run into the case-har...

Making Steel Balls
Steel balls are made from rods or coils according to size, st...

Heavy Forging Practice
In heavy forging practice where the metal is being worked at...

Hardening Carbon Steel For Tools
For years the toolmaker had full sway in regard to make of st...

Molybdenum
Molybdenum steels have been made commercially for twenty-five...



The Packing Department






Category: HEAT TREATMENT OF STEEL

In Fig. 56 is shown the packing pots where
the work is packed. These are of malleable cast iron, with an internal
vertical flange around the hole A. This fits in a bell on the
end of the cast-iron pipe B, which is luted in position with
fireclay before the packing begins. At C is shown a pot ready
for packing. The crown gears average 10 to 12 in. in diameter and
weigh about 11 lb. each. When placed in the pots, they surround
the central tube, which allows the heat to circulate. Each pot
contains five gears. Two complete scrap gears are in each furnace
(i.e., gears which fail to pass machining inspection), and at
the top of front pot are two or more short segments of scrap gear,
used as test pieces to gage depth of case.



After filling to the top with compound, the lid D is luted on.
Ten pots are then placed in a furnace. It will be noted that the
pots to the right are numbered 1, 2, 3, 4, indicating the position
they are to occupy in the furnace.

The cast-iron ball shown at E is small enough to drop through
the pipe B, but will not pass through the hole A in the bottom
of the pot. It is used as a valve to plug the bottom of the pot
to prevent the carburizing compound from dropping through when
removing the carburized gears to the quenching bath.

Without detracting from the high quality of the work, the metallurgist
in this plant has succeeded in cutting out one entire operation
and reducing the time in the hardening room by about 24 hr.

Formerly, the work was carburized at about 1,700 deg.F. for 9 hr. The
pots were then run out into the yard and allowed to cool slowly.
When cool, the work was taken out of the pots, reheated and quenched
at 1,600 deg.F. to refine the core. It was again reheated to 1,425 deg.F.
and quenched to refine the case. Finally, it was drawn to the proper
temper.





Next: Short Method Of Treatment

Previous: Heat-treating Department



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