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Steel Making

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

Preventing Carburizing By Copper-plating
Copper-plating has been found effective and must have a thick...

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

Hardening High-speed Steels
We will now take up the matter of hardening high-speed steels...

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

Phosphorus
PHOSPHORUS is an element (symbol P) which enters the metal fr...

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

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

For Milling Cutters And Formed Tools
FORGING.--Forge as before.--ANNEALING.--Place the steel in a ...

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

S A E Heat Treatments
The Society of Automotive Engineers have adopted certain heat...

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

Cyanide Bath For Tool Steels
All high-carbon tool steels are heated in a cyanide bath. Wi...

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...

Furnace Data
In order to give definite information concerning furnaces, fu...

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

Heat-treating Department
The heat-treating department occupies an L-shaped building. ...

Care In Annealing
Not only will benefits in machining be found by careful anne...

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

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



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



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