Auto Suggestion.ca - Download the EBook Self MasteryInformational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Hints For Tool Steel Users
Do not hesitate to ask for information from the maker as to t...

Annealing To Relieve Internal Stresses
Work quenched from a high temperature and not afterward tempe...

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

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

Nickel-chromium
A combination of the characteristics of nickel and the charac...

Manganese
MANGANESE is a metal much like iron. Its chemical symbol is M...

Annealing
There is no mystery or secret about the proper annealing of d...

Classifications Of Steel
Among makers and sellers, carbon tool-steels are classed by g...

Effect Of A Small Amount Of Copper In Medium-carbon Steel
This shows the result of tests by C. R. Hayward and A. B. Joh...

Impact Tests
Impact tests are of considerable importance as an indication ...

Carburizing Low-carbon Sleeves
Low-carbon sleeves are carburized and pushed on malleable-ir...

Carbon Steels For Different Tools
All users of tool steels should carefully study the different...

Pyrometers
Armor plate makers sometimes use the copper ball or Siemens' ...

Surface Carburizing
Carburizing, commonly called case-hardening, is the art of pr...

Bessemer Process
The bessemer process consists of charging molten pig iron int...

Case-hardening Treatments For Various Steels
Plain water, salt water and linseed oil are the three most co...

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

The Theory Of Tempering
Steel that has been hardened is generally harder and more br...

Protectors For Thermo-couples
Thermo-couples must be protected from the danger of mechanica...

Standard Analysis
The selection of a standard analysis by the manufacturer is t...



Annealing To Relieve Internal Stresses






Category: HARDENING CARBON STEEL FOR TOOLS

Work quenched from a high temperature and not afterward tempered
will, if complex in shape, contain many internal stresses which may
later cause it to break. They may be eased off by slight heating
without materially lessening the hardness of the piece. One way
to do this is to hold the piece over a fire and test it with a
moistened finger. Another way is to dip the piece in boiling water
after it has first been quenched in a cold bath. Such steps are
not necessary with articles which will afterward be tempered and
in which the strains are thus reduced.

In annealing steels the operation is similar to hardening, as far
as heating is concerned. The critical temperatures are the proper
ones for annealing as well as hardening. From this point on there
is a difference, for annealing consists in cooling as slowly as
possible. The slower the cooling the softer will be the steel.

Annealing may be done in the open air, in furnaces, in hot ashes
or lime, in powdered charcoal, in burnt bone, in charred leather
and in water. Open-air annealing will do as a crude measure in
cases where it is desired to take the internal stresses out of
a piece. Care must be taken in using this method that the piece
is not exposed to drafts or placed on some cold substance that
will chill it. Furnace annealing is much better and consists in
heating the piece in a furnace to the critical temperature and
then allowing the work and the furnace to cool together.

When lime or ashes are used as materials to keep air away from
the steel and retain the heat, they should be first heated to make
sure that they are dry. Powdered charcoal is used for high-grade
annealing, the piece being packed in this substance in an iron box
and both the work and the box raised to the critical temperature
and then allowed to cool slowly. Machinery steel may be annealed in
spent ground-bone that has been used in casehardening; but tool
steel must never be annealed in this way, as it will be injured
by the phosphorus contained in the bone. Charred leather is the
best annealing material for high-carbon steel, because it prevents
decarbonizing taking place.





Next: Double Annealing

Previous: Preventing Decarbonization Of Tool Steel



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 4254