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

Nickel
Nickel may be considered as the toughest among the non-rare a...

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

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

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

Heat Treatment Of Punches And Dies Shears Taps Etc
HEATING.--The degree to which tools of the above classes shou...

Heating
Although it is possible to work steels cold, to an extent de...

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

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

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

The Quenching Tank
The quenching tank is an important feature of apparatus in c...

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

Preparing Parts For Local Case-hardening
At the works of the Dayton Engineering Laboratories Company, ...

The Care Of Carburizing Compounds
Of all the opportunities for practicing economy in the heat-t...

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

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

Pyrometers For Molten Metal
Pyrometers for molten metal are connected to portable thermoc...

Fatigue Tests
It has been known for fifty years that a beam or rod would fa...

Annealing Method
Forgings which are too hard to machine are put in pots with ...

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...

Silicon
SILICON is a very widespread element (symbol Si), being an es...



Pyrometry And Pyrometers






Category: PYROMETRY AND PYROMETERS

A knowledge of the fundamental principles of pyrometry, or the
measurement of temperatures, is quite necessary for one engaged
in the heat treatment of steel. It is only by careful measurement
and control of the heating of steel that the full benefit of a
heat-treating operation is secured.

Before the advent of the thermo-couple, methods of temperature
measurement were very crude. The blacksmith depended on his eyes
to tell him when the proper temperature was reached, and of course
the color appeared different on light or dark days. Cherry
to one man was orange to another, and it was therefore almost
impossible to formulate any treatment which could be applied by
several men to secure the same results.

One of the early methods of measuring temperatures was the iron
ball method. In this method, an iron ball, to which a wire was
attached, was placed in the furnace and when it had reached the
temperature of the furnace, it was quickly removed by means of
the wire, and suspended in a can containing a known quantity of
water; the volume of water being such that the heat would not cause
it to boil. The rise in temperature of the water was measured by a
thermometer, and, knowing the heat capacity of the iron ball and
that of the water, the temperature of the ball, and therefore the
furnace, could be calculated. Usually a set of tables was prepared
to simplify the calculations. The iron ball, however, scaled, and
changed in weight with repeated use, making the determinations
less and less accurate. A copper ball was often used to decrease
this change, but even that was subject to error. This method is
still sometimes used, but for uniform results, a platinum ball,
which will not scale or change in weight, is necessary, and the
cost of this ball, together with the slowness of the method, have
rendered the practice obsolete, especially in view of modern
developments in accurate pyrometry.





Next: Pyrometers

Previous: Furnace Data



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 4060