Mississippi Federal Writers Slave Autobiographies Smith Hodges, Ex-Slave, Pike County FEC Mrs. W.F. Holmes [FANNY SMITH HODGES Berglundtown, Mississippi] Fanny Smith Hodges lives in Berglundtown, in the northern part of town, in the ... Read more of Fanny Smith Hodges at Martin Luther King.caInformational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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

Crankshaft
The crankshaft was the most highly stressed part of the entir...

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

Phosphorus
Phosphorus is one of the impurities in steel, and it has been...

Judging The Heat Of Steel
While the use of a pyrometer is of course the only way to hav...

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

Temperature Recording And Regulation
Each furnace is equipped with pyrometers, but the reading an...

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

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

Double Annealing
Water annealing consists in heating the piece, allowing it to...

A Chromium-cobalt Steel
The Latrobe Steel Company make a high-speed steel without tun...

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

Sulphur
SULPHUR is another element (symbol S) which is always found i...

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

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

Calibration Of Pyrometer With Common Salt
An easy and convenient method for standardization and one whi...

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

Corrosion
This steel like any other steel when distorted by cold worki...

Heat Treatment Of Milling Cutters Drills Reamers Etc
THE FIRE.--Gas and electric furnaces designed for high heats ...

The Packing Department
In Fig. 56 is shown the packing pots where the work is packe...



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 3406