| Partner: Tatsuo Inoue |
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Ostatnie publikacje
| 1. | Inoue T.♦, Raniecki B., Determination of thermal-hardening stress in steels by use of thermoplasticity theory, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, ISSN: 0022-5096, DOI: 10.1016/0022-5096(78)90008-X, Vol.26, No.3, pp.187-212, 1978 Streszczenie: The problems of quenching-stress analysis are critically reviewed and an adequate simple theory is discussed. The theory accounts for both plasticity and volumetric changes due to phase transformation accompanying the thermal-hardening of a group of simple steels that are characterized by C-shaped time-temperature-transformation diagrams. The volume dilatation in the absence of stress is assumed to be a linear function of the separate specific volumes and weight fractions of the constituents (pearlite, austenite and martensite). With use of the classical relationships of a formal theory of transformation kinetics, the amounts of pearlite and martensite are expressed in terms of the temperature and the temperature-history. The specific forms of such functions are given. In order to account for the influence of phase transformation on plastic properties, the non-isothermal plastic flow-rule is generalized, and a thermal-hardening parameter is introduced which is identified with the amount of pearlite. Variational principles and bounding inequalities associated with the fundamental rate-problem are considered. As an example, the problem for a rapidly, uniformly-cooled half-space is solved. The variations of the residual stress and the final amount of martensite with distance from the outer surface are given, for several values of the rate-of-cooling. The results suggest that the residual stress vanishes on the plane containing approximately 30–35 per cent of martensite. Afiliacje autorów:
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| 2. | Raniecki B., Inoue T.♦, Kinetics of Phase Transformations and Analysis of Stresses due to Quenching of Steel, Journal of the Society of Materials Science, ISSN: 0514-5163, DOI: 10.2472/jsms.26.935, Vol.26, No.289, pp.935-940, 1977 Streszczenie: Kinetics of phase transformations in steel during quenching is presented. The transformations form austenite to pearlite and to martensite are characterized as a function of thermal history, and the volumetric change of an element is discussed. A plastic flow rule including such effects of structural changes is proposed in the second part of this paper. A numerical example is shown for a semi-infinite body cooled at the surface from an eutectoid temperature. Afiliacje autorów:
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