notched Charpy specimen

- all-weld-metal specimen

1. образец

2. пробный экземпляр

3. проба

4. пробный брусок

SUBJECT AREA: Metallurgy

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After graduating in chemistry from the Ecole Polytechnique in 1887, Charpy continued to work there on the physical chemistry of solutions for his doctorate. He joined the Laboratoire d'Artillerie de la Marine in 1892 and began to study the structure and mechanical properties of various steels in relation to their previous heat treatment. His first memoir, on the mechanical properties of steels quenched from various temperatures, was published in 1892 on the advice of Henri Le Chatelier. He joined the Compagnie de Chatillon Commentry Fourchamboult et Decazeville at their steelworks in Imphy in 1898, shortly after the discovery of Invar by G.E. Guillaume. Most of the alloys required for this investigation had been prepared at Imphy, and their laboratories were therefore well equipped with sensitive and refined dilatometric facilities. Charpy and his colleague L.Grenet utilized this technique in many of their earlier investigations, which were largely concerned with the transformation points of steel. He began to study the magnetic characteristics of silicon steels in 1902, shortly after their use as transformer laminations had first been proposed by Hadfield and his colleagues in 1900. Charpy was the first to show that the magnetic hysteresis of these alloys decreased rapidly as their grain size increased.

The first details of Charpy's pendulum impact testing machine were published in 1901, about two years before Izod read his paper to the British Association. As with Izod's machine, the energy of fracture was measured by the retardation of the pendulum. Charpy's test pieces, however, unlike those of Izod, were in the form of centrally notched beams, freely supported at each end against rigid anvils. This arrangement, it was believed, transmitted less energy to the frame of the machine and allowed the energy of fracture to be more accurately measured. In practice, however, the blow of the pendulum in the Charpy test caused visible distortion in the specimen as a whole. Both tests were still widely used in the 1990s.

In 1920 Charpy left Imphy to become Director-General of the Compagnie des Aciéries de la Marine et Homecourt. After his election to the Académie des Sciences in 1918, he came to be associated with Floris Osmond and Henri Le Chatelier as one of the founders of the "French School of Physical Metallurgy". Around the turn of the century he had contributed much to the development of the metallurgical microscope and had helped to introduce the Chatelier thermocouple into the laboratory and to industry. He also popularized the use of platinum-wound resistance furnaces for laboratory purposes. After 1920 his industrial responsibilities increased greatly, although he continued to devote much of his time to teaching at the Ecole Supérieure des Mines in Paris, and at the Ecole Polytechnique. His first book, Leçons de Chimie (1892, Paris), was written at the beginning of his career, in association with H.Gautier. His last, Notions élémentaires de sidérurgie (1946, Paris), with P.Pingault as co-author, was published posthumously.

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f <qualit.mat> ■ Charpy notched-bar impact test specimen; Charpy test specimen pract

m prakt <qualit.mat> ■ Charpy notched-bar impact test specimen; Charpy test specimen pract

<qualit.mat> ■ Charpy-Kerbschlagbiegeprobe f ; Charpy-Probekörper m prakt