Junghans, Siegfried

SUBJECT AREA: Metallurgy

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b. 1887

d. 1954

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German pioneer of the continuous casting of metals.

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Junghans was of the family that owned Gebrüder Junghans, one of the largest firms in the German watch-and clockmaking industry. From 1906 to 1918 he served in the German Army, after which he took a course in metallurgy and analytical chemistry at the Technical High School in Stuttgart. Junghans was then given control of the brassworks owned by his family. He wanted to make castings simply and cheaply, but he found that he lacked the normal foundry equipment. By 1927, formulating his ideas on continuous casting, he had conceived a way of overcoming this deficiency and began experiments. By the time the firm was taken over by Wieland-Werke AG in 1931, Junghans had achieved positive results. A test plant was erected in 1932, and commercial production of continuously cast metal followed the year after. Wieland told Junghans that a brassfounder who had come up through the trade would never have hit on the idea: it took an outsider like Junghans to do it. He was made Technical Director of Wielands but left in 1935 to work privately on the development of continuous casting for all metals. He was able to license the process for non-ferrous metals during 1936–9 in Germany and other countries, but the Second World War interrupted his work; however, the German government supported him and a production plant was built. In 1948 he was able to resume work on the continuous casting of steel, which he had been considering since 1936. He pushed on in spite of financial difficulties and produced the first steel by this process at Schorndorf in March 1949. From 1950 he made agreements with four firms to work towards the pilot plant stage, and this was achieved in 1954 at Mannesmann's Huckingen works. The aim of continuous casting is to bypass the conventional processes of casting molten steel into ingots, reheating the ingots and shaping them by rolling them in a large mill. Essentially, in continuous casting, molten steel is drawn through the bottom of a ladle and down through a water-cooled copper mould. The unique feature of Junghans's process was the vertically reciprocating mould, which prevented the molten metal sticking as it passed through. A continuous length of steel is taken off and cooled until it is completely solidified into the required shape. The idea of continuous casting can be traced back to Bessemer, and although others tried to apply it later, they did not have any success. It was Junghans who, more than anybody, made the process a reality.

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Further Reading

K.Sperth and A.Bungeroth, 1953, "The Junghans method of continuous casting of steel", Metal Treatment and Drop Forging, Mayn.

J.Jewkes et al., 1969, The Sources of Invention, 2nd edn, London: Macmillan, pp. 287 ff.

LRD