Steelmaking.ca Home Steel Making Categories Manufacturing and the Economy of Machinery

Steel Making

Properties Of Alloy Steels
The following table shows the percentages of carbon, manganes...

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

Conclusions
Martien was probably never a serious contender for the honor ...

Suggestions For Handling High-speed Steels
The following suggestions for handling high-speed steels are ...

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

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

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

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

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

Steel Can Be Worked Cold
As noted above, steel can be worked cold, as in the case of ...

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

Compensating Leads
By the use of compensating leads, formed of the same materia...

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

Heat Treatment Of Lathe Planer And Similar Tools
FIRE.--For these tools a good fire is one made of hard foundr...

Shrinking And Enlarging Work
Steel can be shrunk or enlarged by proper heating and cooling...

The Electric Process
The fourth method of manufacturing steel is by the electric f...

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

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

Tempering Colors On Carbon Steels
Opinions differ as to the temperature which is indicated by t...

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



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 Informational Site Network
Report
Privacy
ADD TO EBOOK


Viewed 4436