VIEW THE MOBILE VERSION of www.steelmaking.ca Informational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Chromium
Chromium when alloyed with steel, has the characteristic func...

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

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

The Thermo-couple
With the application of the thermo-couple, the measurement of...

Steel For Chisels And Punches
The highest grades of carbon or tempering steels are to be re...

The Effect
The heating at 1,600 deg.F. gives the first heat treatment w...

Quality And Structure
The quality of high-speed steel is dependent to a very great ...

Carburizing By Gas
The process of carburizing by gas, briefly mentioned on page ...

Manganese
Manganese adds considerably to the tensile strength of steel,...

Temperature For Annealing
Theoretically, annealing should be accomplished at a tempera...

Shrinking And Enlarging Work
Steel can be shrunk or enlarged by proper heating and cooling...

Quenching Tool Steel
To secure proper hardness, the cooling of quenching of steel ...

An Automatic Temperature Control Pyrometer
Automatic temperature control instruments are similar to the ...

Highly Stressed Parts
The highly stressed parts on the Liberty engine consisted of ...

Ebbw Vale And The Bessemer Process
After his British Association address in August 1856, Besseme...

Tempering Round Dies
A number of circular dies of carbon tool steel for use in too...

Cutting-off Steel From Bar
To cut a piece from an annealed bar, cut off with a hack saw,...

Chrome-nickel Steel
Forging heat of chrome-nickel steel depends very largely on ...

Annealing Of Rifle Components At Springfield Armory
In general, all forgings of the components of the arms manufa...

Pickling The Forgings
The forgings were then pickled in a hot solution of either ni...



For Milling Cutters And Formed Tools






Category: HIGH-SPEED STEEL

FORGING.--Forge as before.--ANNEALING.--Place the steel in a pipe,
box or muffle. Arrange the steel so as to allow at least 1 in.
of packing, consisting of dry powder ashes, powdered charcoal,
mica, etc., between the pieces and the walls of the box or pipe.
If using a pipe close the ends. Heat slowly and uniformly to a
cherry red, 1,375 to 1,450 deg.F. according to size. Hold the steel at
this temperature until the heat has thoroughly saturated through
the metal, then allow the muffle box and tools to cool very slowly
in a dying furnace or remove the muffle with its charge and bury
in hot ashes or lime. The slower the cooling the softer the steel.

The heating requires from 2 to 10 hr. depending upon the size of
the piece.

HARDENING AND TEMPERING.--It is preferable to use two furnaces
when hardening milling cutters and special shape tools. One furnace
should be maintained at a uniform temperature from 1,375 to 1,450 deg.F.
while the other should be maintained at about 2,250 deg.F. Keep the
tool to be hardened in the low temperature furnace until the tool
has attained the full heat of this furnace. A short time should be
allowed so as to be assured that the center of the tool is as hot
as the outside. Then quickly remove the tool from this preheating
furnace to the full heat furnace. Keep the tool in this furnace only
as long as is necessary for the tool to attain the full temperature
of this furnace. Then quickly remove and quench in oil or in a
dry air blast. Remove before the tool is entirely cold and draw
the temper in an oil bath by raising the temperature of the oil
to from 500 to 750 deg.F. and allow this tool to remain, at this
temperature, in the bath for at least 30 min., insuring uniformity
of temper; then cool in the bath, atmosphere or oil.

If higher drawing temperatures are desired than those possible
with oil, a salt bath can be used. A very excellent bath is made
by mixing two parts by weight of crude potassium nitrate and three
parts crude sodium nitrate. These will melt at about 450 deg.F. and
can be used up to 1,000 deg.F. Before heating the steel in the salt
bath, slowly preheat, preferably in oil. Reheating the hardened
high-speed steel to 1,000 deg.F. will materially increase the life
of lathe tools, but milling and form cutters, taps, dies, etc.,
should not be reheated higher than 500 to 650 deg.F., unless extreme
hardness is required, when 1,100 to 1,000 deg.F., will give the hardest
edge.





Next: Instructions For Working High-speed Steel

Previous: Lathe And Planer Tools



Add to del.icio.us Add to Reddit Add to Digg Add to Del.icio.us Add to Google Add to Twitter Add to Stumble Upon
Add to Informational Site Network
Report
Privacy
SHAREADD TO EBOOK


Viewed 2782