This article was originally published in Electrochemical and Metallurgical Industry Publication of April 1907. Information within this article is therefore correct as of 1907. The publication of this material aims to provide historical insight on the subject and its place in industry.
About 12,250,000 gross tons of Bessemer steel ingots were produced in the US in 1906, with a small tonnage of Bessemer steel castings, made from various forms of baby converters. The production of Bessemer steel in the US has been doubling through successive lengthening periods. There is reason to believe that the 1906 production will never be doubled. The first year, 1867, for which statistics were gathered showed a production of 2,679 gross tons. In 1875 the production was 335,283 gross tons. From that year it has required the following periods for a doubling of production 3 years to 1878, 3 years to 1881, 6 years to 1887, 8 years to 1895, and finally 11 years to 1906. In early years new plants were built with avidity, not all were entirely successful. There has been relatively very little building of absolutely new plants, but an enormous advance in the actual production of given plants. Occasionally new plants have been built, but with the completion last summer of the Youngstown Sheet & Tube Co's plant, it is possible that building new plants has ceased. Not until now has a successful steel enterprise abandoned a Bessemer plant, but that is to occur within a few months, when the Carnegie Steel Co removes its Bessemer department at Duquesne, to make way for the 18 basic open-hearth furnaces already under construction.
The year 1890 is a good selection for comparison with the achievement of last year, since in 1890 the regular Bessemer process had been well worked out, the Clapp-Griffiths and Robert-Bessemer processes were distinctly on the decline, and Direct metal was not being used regularly.
The Clapp-Griffiths and Robert-Bessemer converters are not included in our table for 1890. For 1906 we have made a suitable deduction for the production of Bessemer steel castings, and have correspondingly eliminated all the small converters used for the production of castings. This cuts the standard Bessemer converter capacity off with the two 4 1/2-ton vessels operated at Columbus, the smallest converters now in use for the production of Bessemer steel ingots.The results in summary:
| 1890 ||1906|
|Average Rated Capacity per Converter||6.55||10.11|
|Total Ingot Production in Gross Tons||3,580,000||12,250,000|
|Average Output in Tons per Converter||46,493||197,580|
|Average Output per Ton of Rated Converter Capacity|| 7,103 ||18,934|
Three causes have contributed to the increase in output, relative to rated converter capacity, an increase totals 167% in 16 years. The first has been the introduction of the direct metal process with the Jones mixer. The second has been improvement in the auxiliary equipment, necessitating less waiting on the part of the converter. The third has been a more general realization of the economy in forcing production. With direct metal and mixer hotter and more uniform pig iron is furnished the converter, permitting the use of iron with lower silicon content. There is the curious spectacle of standard Bessemer pig iron being defined in contracts today as to contain between 1 and 2% of silicon, while in the large steel works the metal used averages less than 1% silicon. The iron which is sold runs much nearer to 1% than to 2%, and would not lead to further purchases if it hugged 2%. The supply is more dependable with the mixer than when cupolas were used exclusively. The machinery of the converter itself is better, while soaking pit capacity has been greatly increased; interruptions to rolling are less serious, and the increased soaking pit capacity smooths off the irregularities that still come, to a greater extent than formerly.
The tendency to push all capacity to the utmost is such a feature of American steel works operation that it need not be referred to in particular as to its influence in bringing up the output of converters. There was curious reading for American steel works managers two or three years ago, when a history of a "Bessemer shop" in England was given to the Iron and Steel Institute. The writer described how the output per converter had been steadily increased, so that the management found it "could get along" with a much decreased number of converters. An American manager can hardly sleep well if he finds his whole plant is balanced, except that the shear could do more work than it is called upon to perform. There is no likelihood of any important Bessemer steel works being built in the US in the future. A successful Bessemer department is scheduled for abandonment. Others may follow. The output of the existing plants may be increased somewhat, but the blowing operations are already conducted with almost clockwork regularity, the blast furnace has been made completely the servant of the steel works, to furnish exactly the analysis of pig iron required. The pneumatic vessel may not disappear, but increase in numbers. It is being put to the base use of constituting an adjunct to the regular open-hearth process. Probably the principal factor in the extension of this system will be the rate of growth of the demand for steel. With a very rapid growth the scrap outcome will not be sufficient to reduce carbon by mixture, while with a slower growth of demand scrap will come out in steadily increasing quantities, relative to the demand.
Image Credit: The Library of Congress