Gas Consumption For Carburizing

: CASE-HARDENING OR SURFACE-CARBURIZING
: The Working Of Steel

Although the advantages offered by the gas-fired furnace for carburizing

have been generally recognized in the past from points of view as

close temperature regulation, decreased attendance, and greater

convenience, very little information has been published regarding

the consumption of gas for this process. It has therefore been a

matter of great difficulty to obtain authentic information upon

this point, either from
akers or users of such furnaces.



In view of this, the details of actual consumption of gas on a

regular customer's order job will be of interest. The Revergen

furnace, manufactured by the Davis Furnace Company, Luton, Bedford,

England, was used on this job, and is provided with regenerators

and fired with illuminating gas at ordinary pressure, the air being

introduced to the furnace at a slight pressure of 3 to 4 in. water

gage. The material was charged into a cold furnace, raised to 1,652 deg.F.,

and maintained at that temperature for 8 hr. to give the necessary

depth of case. The work consisted of automobile gears packed in

six boxes, the total weight being 713 lb. The required temperature

of 1,652 deg.F. was obtained in 70 min. from lighting up, and a summary

of the data is shown in the following table:



Cubic Foot Total

Per Pound Number of

of Load Cubic Foot

Gas to raise furnace and charge from

cold to 1,652 deg.F., 70 min. 1.29 925

Gas to maintain 1,652 deg.F. for 1st hour 0.38 275

Gas to maintain 1,652 deg.F. for 2nd hour 0.42 300

Gas to maintain 1,652 deg.F. for 3rd hour 0.38 275

Gas to maintain 1,652 deg.F. for 4th hour 0.42 300

Gas to maintain 1,652 deg.F. for 5th hour 0.49 350

Gas to maintain 1,652 deg.F. for 6th hour 0.49 350

Gas to maintain 1,652 deg.F. for 7th hour 0.45 325

Gas to maintain 1,652 deg.F. for 8th hour 0.45 325



The overall gas consumption for this run of 9 hr. 10 min. was only

4.8 cu. ft. per pound of load.



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