Siouan.ca - Download the EBook Sioux MythsInformational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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

Complete Calibration Of Pyrometers
For the complete calibration of a thermo-couple of unknown e...

Connecting Rods
The material used for all connecting rods on the Liberty engi...

Machineability
Reheating for machine ability was done at 100 deg. less than ...

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

Pyrometry And Pyrometers
A knowledge of the fundamental principles of pyrometry, or th...

Using Illuminating Gas
The choice of a carburizing furnace depends greatly on the fa...

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

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

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

Robert Mushet
Robert (Forester) Mushet (1811-1891), born in the Forest of D...

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

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

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

High Speed Steel
For centuries the secret art of making tool steel was handed ...

Mushet And Bessemer
That Mushet was "used" by Ebbw Vale against Bessemer is, perh...

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

Introduction Of Carbon
The matter to which these notes are primarily directed is the...

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

Plant For Forging Rifle Barrels
The forging of rifle barrels in large quantities and heat-tre...



Knowing What Takes Place






Category: HARDENING CARBON STEEL FOR TOOLS

How are we to know if we have given a
piece of steel the very best possible treatment?

The best method is by microscopic examination of polished and etched
sections, but this requires a certain expense for laboratory equipment
and upkeep, which may prevent an ordinary commercial plant from
attempting such a refinement. It is highly recommended that any
firm that has any large amount of heat treatment to do, install
such an equipment, which can be purchased for from $250 to $500.
Its intelligent use will save its cost in a very short time.

The other method is by examination of fractures of small test bars.
Steel heated to its correct temperatures will show the finest possible
grain, whereas underheated steel has not had its grain structure
refined sufficiently, and so will not be at its best. On the other
hand, overheated steel will have a coarser structure, depending
on the extent of overheating.

To determine the proper quenching temperature of any particular
grade of steel it is only necessary to heat pieces to various
temperatures not more than 20 deg.C. (36 deg.F.) apart, quench in water,
break them, and examine the fractures. The temperature producing
the finest grain should be used for annealing and hardening.

Similarly, to determine tempering temperatures, several pieces
should be hardened, then tempered to various degrees, and cooled
in air. Samples, say six, reheated to temperatures varying by 100 deg.
from 300 to 800 deg.C. will show a considerable range of properties,
and the drawing temperature of the piece giving the desired results
can be used.

For drawing tempers up to 500 deg.F. oil baths of fresh cotton seed
oil can be safely and satisfactorily used. For higher temperature
a bath of some kind of fused salt is recommended.





Next: Hints For Tool Steel Users

Previous: Temperatures To Use



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 3045