ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The goal of this work is to model the temperature distribution, phase transformation andresidual stresses induced during the heat treatment of 3 and 5 inches diameter grinding balls. In thefirst step, the radial distribution of temperature inside the balls was calculated and validatedexperimentally. During the quenching, the model considers factors such as the heating of the waterand the formation of a steam layer that surrounds the balls in the beginning of the treatment. In asecond step, with the temperature distribution, the CCT curves of the steel and the Koistinen-Marburger equation, the radial distribution of martensite was determined during the heat treatment.Finally, in the third step, the residual stresses field was modeled considering the temperaturedistribution, the force equilibrium equations and the constitutive thermo-elastic relationships, wherethe expansion due to the austenite – martensite transformation was included.In the temperature distribution, a good experimental-theoretical agreement was obtained, withdifferences at the end of the quenching no higher than 0,5 %. Respect to the residual stresses, themodel indicates that the maximum tensile values occur at certain depth below the surface of theballs and the experimental evidence of the behavior of the balls in a mill simulator, as well as themeasured residual stresses by means of DRX shows an acceptable agreement with the theoreticalpredictions
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.2234.pdf
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