Determination method of thermal-deformation microstructure evolution mechanisms and thermal machining performance of C-Mn-Al high-strength steel

Abstract

The invention belongs to the technical field of high-strength steel machining engineering, and particularly relates to a determination method of thermal-deformation microstructure evolution mechanismsand thermal machining performance of C-Mn-Al high-strength steel. According to the method, firstly, a high-temperature compression test is carried out on the novel C-Mn-Al high-strength steel, and true stress-true strain curve data of the steel are obtained; then a rheology stress prediction model of the steel is established, model selection is based on creep theory, a class of constitutive models which are of relationships of Young's modulus and a self-diffusion coefficient of austenite and temperature and have physics bases are considered, and the established constitutive model can accurately predict rheology stress of the steel; a thermal-deformation machining graph of the steel is established, and microstructures are combined to determine the microstructure evolution mechanisms of different regions in the machining graph. The constitutive model of thermal deformation and the machining graph are combined, the thermal-deformation rheology stress and thermal-deformation power dissipation efficiency under arbitrary deformation conditions are analyzed, thus the corresponding microstructure evolution mechanisms and thermal machining performance information are obtained, and resultshave great significance for thermal machining process control of the high-strength steel.

Description

technical field [0001] The invention belongs to the technical field of high-strength steel processing engineering, and particularly relates to a method for determining the thermal deformation microstructure evolution mechanism and thermal processing performance of C-Mn-Al high-strength steel. Background technique [0002] In order to save energy and protect the environment, it is urgent to develop high-strength steels with good ductility and toughness, including TRIP steels. Conventional TRIP steels were developed based on the C-Mn-Si alloy system. The purpose of using high silicon content is to suppress the formation of cementite during cooling so as to increase the stability and quantity of retained austenite. However, high silicon content may cause steel defects such as hard oxide layer, poor surface properties and low coating ability. Since the substitution of Al for Si can eliminate these harmful effects of Si, C-Mn-Al-Si or C-Mn-Al-based TRIP steels have attracted mor...

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Problems solved by technology

However, the application still uses the traditional hyperbolic sine constitutive model, and the accuracy of its prediction results still needs to be further improved

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