A method of correction of traditional and reconstration model

Abstract

The invention relates to the field of material microstructure analysis, in particular to a method for correcting traditional recrystallization models. Obtain samples under different deformation conditions through a physical simulation testing machine, and observe the recrystallization fraction of the core; use numerical simulation software to obtain the real strain of the core of the sample; perform function fitting on the obtained data to obtain model parameters; calculate the traditional inflection point method The inaccuracy of the critical strain and the error caused by the uneven local strain of the compressed sample were corrected; the obtained model parameters were fitted with the Zener-Hollomon parameters to obtain the recrystallization model parameters under other conditions. The corrected recrystallization model of the invention is not only applicable to the recrystallization prediction of single-phase alloys, but also applicable to the recrystallization prediction of multi-phase alloys, and meanwhile the prediction accuracy is greatly improved. Combined with the finite element software, it can quantitatively analyze the change of the dynamic recrystallization volume fraction of the material, and provide a scientific basis for the formulation of the actual processing technology of the material.

Description

technical field [0001] The invention relates to the field of material microstructure analysis, in particular to a correction method for a traditional recrystallization fraction prediction model. Background technique [0002] The establishment process of the conventional recrystallization fraction prediction model is as follows: the strain hardening rate of the material is obtained by deriving the true stress-strain curve of the high temperature compression test, and the recrystallization critical strain and the maximum softening rate strain are determined by analyzing the inflection point of the hardening rate, and then according to the empirical formula A mathematical relationship model between the critical strain and the maximum softening rate strain was established to predict the dynamic recrystallization volume fraction. Therefore, the model requires few parameters and has a simple form, so it is widely used. [S.I.Kim, et. al Mater. Sci. Eng. A 311 (2001) 108.8051. Z. Y...

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Problems solved by technology

[0003] The accuracy of the conventional model mainly depends on the accuracy of the critical strain and the maximum softening rate strain, but it is often difficult to obtain accurate strain data due to the following reasons: (i) Using physical simulation of thermal compression experiments, due to the existence of friction, the entire sample Inhomogeneous deformation, the measured data is the overall mechanical property data including inhomogeneous deformation; (ii) and for some multi-phase alloys, the inflection point of the strain hardening rate curve is not necessarily caused by material recrystallization softening, but may be caused by material strengthening caused by phase softening, which is not considered in the limitations of traditional methods

(iii) The original compression curve often fluctuates greatly, and the accurate recrystallization critical strain and maximum softening rate curve cannot be obtained directly from the hardening rate curve. At present, the commonly used method is to smooth the original stress-strain curve through various functions, but the approximate Processing makes the original curve more distorted

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