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

Brown Automatic Signaling Pyrometer
In large heat-treating plants it has been customary to mainta...

Tungsten
Tungsten, as an alloy in steel, has been known and used for a...

Annealing Method
Forgings which are too hard to machine are put in pots with ...

Affinity Of Nickel Steel For Carbon
The carbon- and nickel-steel gears are carburized separately...

The Electric Process
The fourth method of manufacturing steel is by the electric f...

Forging High-speed Steel
Heat very slowly and carefully to from 1,800 to 2,000 deg.F....

Effect Of Different Carburizing Material
[Illustrations: FIGS. 33 to 37.] Each of these different p...

Preparing Parts For Local Case-hardening
At the works of the Dayton Engineering Laboratories Company, ...

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...

Piston Pin
The piston pin on an aviation engine must possess maximum res...

Compensating Leads
By the use of compensating leads, formed of the same materia...

The Effect Of Tempering On Water-quenched Gages
The following information has been supplied by Automatic and ...

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

Pyrometers For Molten Metal
Pyrometers for molten metal are connected to portable thermoc...

Air-hardening Steels
These steels are recommended for boring, turning and planing...

Liberty Motor Connecting Rods
The requirements for materials for the Liberty motor connecti...

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

William Kelly's Air-boiling Process
An account of Bessemer's address to the British Association w...

Heat-treating Equipment And Methods For Mass Production
The heat-treating department of the Brown-Lipe-Chapin Company...

The Leeds And Northrup Potentiometer System
The potentiometer pyrometer system is both flexible and subst...



Quenching Tool Steel






Category: HARDENING CARBON STEEL FOR TOOLS

To secure proper hardness, the cooling of quenching of steel is
as important as its heating. Quenching baths vary in nature, there
being a large number of ways to cool a piece of steel in contrast
to the comparatively few ways of heating it.

Plain water, brine and oil are the three most common quenching
materials. Of these three the brine will give the most hardness,
and plain water and oil come next. The colder that any of these
baths is when the piece is put into it the harder will be the steel;
but this does not mean that it is a good plan to dip the heated
steel into a tank of ice water, for the shock would be so great
that the bar would probably fly to pieces. In fact, the quenching
bath must be sometimes heated a bit to take off the edge of the
shock.

Brine solutions will work uniformly, or give the same degree of
hardness, until they reach a temperature of 150 deg.F. above which
their grip relaxes and the metals quenched in them become softer.
Plain water holds its grip up to a temperature of approximately
100 deg.F.; but oil baths, which are used to secure a slower rate of
cooling, may be used up to 500 deg. or more. A compromise is sometimes
effected by using a bath consisting of an inch or two of oil floating
on the surface of water. As the hot steel passes through the oil,
the shock is not as severe as if it were to be thrust directly
into the water; and in addition, oil adheres to the tool and keeps
the water from direct contact with the metal.

The old idea that mercury will harden steel more than any other
quenching material has been exploded. A bath consisting of melted
cyanide of potassium is useful for heating fine engraved dies and
other articles that are required to come out free from scale. One
must always be careful to provide a hood or exhaust system to get
rid of the deadly fumes coming from the cyanide pot.

The one main thing to remember in hardening tool steel is to quench
on a rising heat. This does not mean a rapid heating as a slow
increase in temperature is much better in every way.





Next: The Theory Of Tempering

Previous: Double Annealing



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 3149