A method for measuring static recrystallization volume fraction of materials

Abstract

The invention discloses a method for measuring the static recrystallization volume fraction of a material. A group of single-pass compression tests are performed using a thermal simulation testing machine to obtain a stress-strain curve, and data fitting and differential operations are performed to obtain the work hardening rate and the corresponding The relationship curve between stresses, and the critical strain ε at which dynamic recrystallization occurs can be judged from the inflection point in the curve c ; A group of double-pass compression tests are carried out using a thermal simulation testing machine, the total deformation of the double-pass is less than that of the single-pass, and the deformation of each pass in the double-pass compression test ε 0 are less than the critical strain ε of dynamic recrystallization determined by the single-pass compression test c ; Use polynomials to fit the stress-strain curves in single pass and double pass respectively, and perform integral operations respectively to obtain the corresponding strain energy; finally calculate the static recrystallization volume fraction. The invention considers the influence of recovery and dynamic recrystallization on the static recrystallization volume fraction, and can more accurately measure the austenite static recrystallization volume fraction of iron and steel materials.

Description

technical field [0001] The invention relates to a method for measuring the structure evolution of materials during rolling, in particular to a method for measuring the static recrystallization volume fraction of materials. Background technique [0002] During the thermal forming process of the material, two processes of work hardening and recovery and recrystallization softening will occur simultaneously in the interior. There are dynamic recrystallization, subdynamic recrystallization and static recrystallization in the recrystallization mode, and static recrystallization is also an important softening mode in the process of processing. It is of great significance to study the law of static recrystallization of materials during the forming process to control the microstructure and properties during thermal processing. [0003] For new steel grades or new processes, the premise of the research on the mathematical model of the structure change at the rolling pass interval is...

AI Technical Summary

Problems solved by technology

For example, the 0.2% compensation method, 2% compensation method, and 5% total strain method are calculated based on a certain stress value, which is prone to accidental and systematic errors. The existing area method or average stress method does not clearly stipulate the double pass The deformation conditions and the amount of deformation used for the calculation need to rely on the extrapolation model, which will lead to different results obtained by different researchers, especially in the case of dynamic recrystallization of the material during deformation, which is still calculated according to the existing method. The results are unscientific and unreasonable

Images