Effect of Material Anisotropy on the Mechanical Response of Automotive Steel under High Strain Rates

Abstract

A constitutive model for automobile steel with high elongation needs to be established to predict the dynamic deformation behavior under hydroforming applications. In order to clarify the confusing discrepancy in the essential parameters of the classical Cowper-Symonds (C-S) model, a series of automobile structural steels have been employed to investigate the strain rate response by conducting tensile dynamic deformation. Metallographic microscopy and orientation distribution functions were used to characterize the microstructure and texture components of the steels. The microstructure observation discloses that the matrix of all steels is mainly of ferrite and the texture constituent provides a framework for steel to withstand external deformation. The C-S model can be applied to simulate the dynamic deformation with satisfied expectations. It is concluded that the essential parameters D and p in the model show a specific relationship with the steel grade, and the parameter D is proportional to the steel grade and related to material anisotropy, while the parameter p is inversely proportional to the steel grade and has close links with the grain boundary characteristics.

Characterization and Modelling of Manufacturing–Microstructure–Property–Mechanism Relationship for Advanced and Emerging Materials

“…They successfully improved the wear and corrosion resistance of an AZ91D alloy by introducing an Al-Si alloy coating with an addition of Y 2 O 3 , using a laser cladding process. Yin et al [ 33 ] studied the microstructures and textures of various automobile steels and their influences on quasistatic tensile deformation behavior, with a strain rate of 0.001 s −1 and dynamic tensile deformation behaviors with a wide strain rate range, varying from 33 to 600 s −1 . Zhang et al [ 34 ] investigated the relationship between an ultrasonic vibration treatment and the microstructure evolution during the high-temperature forming process of 9310 steel.…”