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:
By means of superplastic tensile test above the Ac1 temperature (γ→α transformationtemperature), superplastic deformation activation energy of ultrafine-grained commercial die steelCrWMn is investigated on the basis of the Arrhenius theory equation, exp( / )1ε& = Aσ m −Q RT , whichindicates the resistance of the superplastic deformation. According to the Arrhenius equation, theactivation energy is estimated from the log σt vs 1/T relationship at a constant of sensitivity index ofstrain rate. The results show that the strain rate sensitivity index is a constant and rather high at theconditions of superplastic deformation for the CrWMn steel, the activation energy for superplasticdeformation of steel CrWMn above the critical temperature is 187KJ/mol, and the superplasticdeformation activation energy is approached to the grain boundary diffusion activation energy of γ-Fe.This indicates that the grain boundary sliding (GBS) in superplastic deformation of CrWMn steel iscontrolled by grain boundary diffusion. The characters of superplastic deformation of the steel abovethe critical temperature, on the other hand, are also analyzed in this paper
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.551-552.341.pdf
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