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

The Modern Hardening Room
A hardening room of today means a very different place from ...

Steel Before The 1850's
In spite of a rapid increase in the use of machines and the ...

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

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

Separating The Work From The Compound
During the pulling of the heat, the pots are dumped upon a ca...

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

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

Application To The Automotive Industry
The information given on the various parts of the Liberty eng...

Tensile Properties
Strength of a metal is usually expressed in the number of pou...

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

Hardening Operation
Hardening a gear is accomplished as follows: The gear is tak...

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

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

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

Gears
The material used for all gears on the Liberty engine was sel...

Preventing Cracks In Hardening
The blacksmith in the small shop, where equipment is usually ...

Heat Treatment Of Steel
Heat treatment consists in heating and cooling metal at defin...

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

Correction By Zero Adjustment
Many pyrometers are supplied with a zero adjuster, by means ...

Oil-hardening Steel
Heat slowly and uniformly to 1,450 deg.F. and forge thorough...



Hardening High-speed Steels






Category: HIGH-SPEED STEEL

We will now take up the matter of hardening high-speed steels. The
most ordinary tools used are for lathes and planers. The forging
should be done at carbon-steel heat. Rough-grind while still hot
and preheat to about carbon-steel hardening heat, then heat quickly
in high-speed furnace to white heat, and quench in oil. If a very
hard substance is to be cut, the point of tool may be quenched in
kerosene or water and when nearly black, finish cooling in oil.
Tempering must be done to suit the material to be cut. For cutting
cast iron, brass castings, or hard steel, tempering should be done
merely to take strains out of steel.

On ordinary machinery steel or nickel steel the temper can be drawn
to a dark blue or up to 900 deg.F. If the tool is of a special form
or character, the risk of melting or scaling the point cannot be
taken. In these cases the tool should be packed, but if there is
no packing equipment, a tool can be heated to as high heat as is
safe without risk to cutting edges, and cyanide or prussiate of
potash can be sprinkled over the face and then quenched in oil.

Some very adverse criticism may be heard on this point, but experience
has proved that such tools will stand up very nicely and be perfectly
free from scales or pipes. Where packing cannot be done, milling
cutters, and tools to be hardened all over, can be placed in muffled
furnace, brought to 2,220 deg. and quenched in oil. All such tools,
however, must be preheated slowly to 1,400 to 1,500 deg. then placed in
a high-speed furnace and brought up quickly. Do not soak high-speed
steel at high heats. Quench in oil.

We must bear in mind that the heating furnace is likely to expand
tools, therefore provision must be made to leave extra stock to
take care of such expansion. Tools with shanks such as counter
bores, taps, reamers, drills, etc., should be heated no further
than they are wanted hard, and quench in oil. If a forge is not
at hand and heating must be done, use a muffle furnace and cover
small shanks with a paste from fire clay or ground asbestos. Hollow
mills, spring threading dies, and large cutting tools with small
shanks should have the holes thoroughly packed or covered with
asbestos cement as far as they are wanted soft.





Next: Cutting-off Steel From Bar

Previous: Quality And Structure



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 2962