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OPEN-HEARTH FURVACE

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Per cent
Metal Charged

Price 10.82 Pig Iron Delaware..

51.00 Robersonia

50.00 10.82

50.70 Scrap 40.40 Foundry Accumulations

18.00 0.87 Foundry Scrap Casting ..

18.00 8.80 Castings from Scrap Dept

18.00 2.45 Scrap 0.06 Unguaranteed.

21.25 18.08 Scrap 0.04 Guaranteed.

24.78 16.10 Bundled Sheet

12.05 87.00

18.37 Special Metals 0.52 Ferrosilicon

155.00 1.29 Ferromanganese

.225.00 0.01 Wash Metal

71.20 0.11 Aluminum Titanium

.166.90 Silico Manganese

..270.00 Aluminum

0.175 0.21 Iron Ore

9.16 0.04 Spiegeleisen

60.00 2.18

180.91 100.00 Total Metal Charged..

25.42
Molten Metal Cost

Cost of Metals
Direct Labor

Items of expense (per Detail below) 10.00: Total cost of inelt

8.00 Shrinkage 92.00 Cost of Metal in Ladle. 35.66 Credit-Scrap Produced.

16.05 56 3.1 riood Casting Produced..

Summary of Expense
Fuel Oil-0. H. Fur., Gallons.. 0.079
Furnace Bottom Sand.

4.47
Ladle Repairs
Furnace Repairs (Actual-Labor and

Material)
Depreciation (10 per cent on orig-

G. T.
G. T.
G. T.
G. T.
G. T.
Lb.
G. T.
G. T.
G. T.
G. T.

0.02 0.02 3.52 22.70

22.70 0.83 9.95 33.48

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inal cost) Expense Labor

Expense, All Other. Total Melting Expense.

0.98 1.46 2.62 9.95

Heats poured, 162.
Average weight per heat, 37,358 pounds.
Metal melted per 100 gallons oil, 4500 pounds.
Fuel oil per net ton melted, 44.4.

were

from the figures which follow, that the costs of the electric furnace are comparable when it is considered that the product of the electric furnace is superior and is fully meeting chemical and physical requirements. It will be noted that in analyzing costs the kilowatt consumption per net ton in the ladle is 720. This apparent high consumption is due to the fact that 60 per cent of all heats are double slagged. A very conservative estimate for single slag heats, operating according to our practice, is 650 kilowatts. The power charge of $1.25 per 100 kilowatts is abnormally high. A material saving in labor costs could be efiected by employing a mechanical charging device which would reduce the charging time.

During the 4-month period, used as a basis for cost comparison, both the electric and open-hearth furnaces operating on short time, due to lack of business. Also it should be remembered that we are comparing figures of a 6-ton basic electric furnace against a 20-ton open-hearth acid furnace. There are a number of items entering into the cost of both processes which would be somewhat modified providing both were run at full capacity. It is indeed uncertain and unreliable to make up figures in any other way than on the basis of actual running cost. The figures are presented on this basis in hopes they will serve as a means of comparison and be of material benefit to foundrymen.

In analyzing costs, the metal charge of $11.18 per net ton for the electric furnace should be noted. Substituting steel turnings at $8.50, gross ton, in place of 0.06 scrap which was used, would reduce the metal charge by $1.66 per net ton of melt. This mixture is practical and would have been used in our case if turnings had been available at the time.

Analyzing Comparative Costs The cost of special metals for the electric furnace was $2.28 per net ton. For actual comparison we should eliminate *the charge for nickel and copper, replacing 1749 pounds with ordinary scrap. This would reduce the special metal charge 49c per net ton.

In analyzing the expense items of the electric furnace, a current charge of $1 instead of $1.25 per 100 kilowatts should be assumed. This item would be reduced $1.80 per net ton of melt. The fuel oil charge for the open hearth is $7.90 per 100 gallons. A very conservative price for oil would be $5 per 100 gallons. The fuel oil consumption, as shown in cost, is 44.4 gallons per net ton of melt. This is high due to furnace operating on short time. If we assume a consumption of 37 gallons per net ton of melt at 5c per gallon, according to our practice, the fuel oil cost per net ton of melt would be reduced $1.85. It should be stated that these figures are not estimates but are actual tank measurements, checked by accurate oil meters, and include the heating of ladle, and week end heating up of furnace.

With the open-hearth furnace operating full time a number of cost items would be materially reduced, as follows:

Direct labor
Expense labor
General expense
Depreciation
Repairs

0.24 per net ton
0.50 per net ton
0.75 per net ton
0.25 per net ton
0.24 per net ton

1.98

Summary of Costs The writer believes that foundrymen will agree that the exceptions above noted are not in the least exaggerated, and are shown for the purpose of presenting the best comparison that the figures will permit, assuming both furnaces are operating under normal and reasonably full time conditions. With the reductions, as above noted, a summary of costs is as follows:

Electric furnace Open-H'th fur. Total metal cost.

9.52 net ton 14.28 net ton Special metals

1.79 net ton

3.52 net ton Expense items

21.58 net ton

6.60 net ton Molten metal cost in ladle........ 36.57 net ton 32.55 net ton

We feel that we were fortunate in having had the opportunity of making observations and comparisons between the two processes covering a period of seven months. We have concluded that, for the special requirements to be met, electric furnace steel is superior to the open-hearth product from a quality viewpoint, and consider the cost comparable with openhearth costs and not prohibitive.

Conclusions
The following are

some of the reasons on which the conclusions are based :

1. Freedom from serious checks in castings, due to absence of oxides, and the lower phosphorus and sulphur content.

2. High temperature easily attained, adapting it for light section casting

3. Carbon and alloy ingots up to 13/2 inches (which we have produced) show marked superiority over ordinary open-hearth product, due to more complete deoxidation of the steel, producing a sounder ingot with less pipe and freedom from segregation, with superior forging and heat-treating qualities.

4. Possibility of taking small portions of heat, producing different compositions from the same heat.

5. Permits of intermiitent running with less damage to furnace than to the open hearth.

6. Flexibility of working in conjunction with open hearth, permitting the casting of pieces beyond the capacity of one furnace.

7. Low cost of furnace charge, practice permitting a charge of 75 per cent steel turnings with 25 per cent foundry scrap, an advantageous low-priced mixture.

8. Low cost of producing a high grade steel for both castings and ingots.

9. Scrap produced by electric furnace used in open hearth as 0.04 material, improving finished product of open hearth at a saving in price of 0.04 material,

Discussion-Comparison of Costs

MR. P. BENDIXEN.--I would like to ask Mr. Ballard what he would substitute for turnings if turnings were not available?

Mr. E. H. BALLARD.--The cheapest boiler plate or forge scrap that can be produced or purchased; what we would call 0.06 or unguaranteed material in proper shape. But ordinarily our experience has been that if we hadn't sold our turnings way ahead of the anticipated requirements we would have had ample. I think the majority of people balance those conditions themselves, and their output would be governed by the cheap low priced scrap that they were producing themselves, but 0.06 or the cheapest scrap would be substituted.

Mr. W. E. MOORE.-. What Mr. Ballard has said regarding the suitability of electric steel for steel foundry use is entirely true. His remarks would, I believe, have been even more favorable to the electric foundry steel, if he had been running an acid instead of a basic electric furnace. While the basic electric furnace is more simple to operate and quicker to put into production than an open-hearth furnace, the acid electric furnace is still more simple to operate and many foundrymen who have had both basic and acid experience maintain that acid electric steel makes sounder castings, on which there is less cost for cleaning and welding.

In one case under my observation they had been making basic steel, keeping four welders busy in the cleaning room, and when they changed to acid electric steel, one welder was all that was necessary to keep up production on the same character and tonnage of castings.

The acid electric furnace show's somewhat lower power and electrode consumption and the refractory life is at least double as compared to basic operation. The acid technique is more simple and more rapid. With the modern rapid type acid electric furnace under favorable conditions, it is possible to get 14 or more heats per day. The heats come so rapidly

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