Influence of Electric Current Pulses on the Microstructure and Mechanical Properties of X70 Pipeline Steel

摘要

The effect of high electric current pulse on the microstructure and macroscopic mechanical behavior of X70 pipeline steel was studied. With the increasing of current density, the grains become refined and the tensile strength has an evident improvement without a decrease in elongation rate. The theoretical analysis shows that two kinds of refinement mechanisms, recrystallization and phase transformation, compete when the exerted current densities differ. Therefore, the ECP treatment should provide a promising method to refine materials and to improve their physical properties by using different current densities.