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INFLUENCE OF THE ULTRASOUNDS ON THE VOLUME FRACTION OF MARTENSITE IN THE MICROSTRUCTURE OF A DUAL-PHASE STEEL
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C. Dulucheanu;T. Severin;M. Baesu
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1314-2704
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English
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17
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61
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In this article, the authors have analysed the influence of ultrasound, used in the quenching from the intercritical range (? + ?), on the volume fraction of martensite in the microstructure of a dual-phase steel with 0.087% C and 0.511% Mn. The ultrasonic oscillations, applied to the medium in which the quenching takes place, under the action of pressure and cavitation phenomenon, destroys and prevents the formation of vapor and gas films, thereby ensuring a more prolonged contact between the workpiece and the cooling medium; in this way the cooling rate is increased, which leads to a cooling more vigorous, the quenching with ultrasounds being more efficient than the classical. The ferrite-martensite microstructures, characteristic of dual-phase steels, were obtained by intercritical quenching that consisted of heating at 760 ?C (for 30 minutes) and cooling in water without mechanical agitation, water in ultrasonic field with frequency of 40 kHz and water in ultrasonic field with frequency of 59 kHz. After heat treatments, metallographic analyses were performed and determined the volume fraction of martensite; using of ultrasounds, and raising their frequency from 40 at 59 kHz, led to increase in the volume fraction of martensite in microstructures, increase contained between 5.70 and 17.58%.
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conference
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17th International Multidisciplinary Scientific GeoConference SGEM 2017
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17th International Multidisciplinary Scientific GeoConference SGEM 2017, 29 June - 5 July, 2017
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Proceedings Paper
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STEF92 Technology
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International Multidisciplinary Scientific GeoConference-SGEM
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Bulgarian Acad Sci; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci & Arts; Slovak Acad Sci; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; World Acad Sci; European Acad Sci, Arts & Letters; Ac
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179-186
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29 June - 5 July, 2017
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website
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cdrom
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4373
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dual-phase steel; ultrasounds; intercritical quenching; volume fraction of martensite
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