Stress--strain behavior of X70 pipeline steel under stress wave loading
应力波载荷作用下X70管线钢的应力-应变行为

The dynamic impact compression experiments for the X70 pipeline steel in rolling condition were carried out using the Hopkinson pressure bar. The structural evolution occurred during the plastic deformation under high strain rate, and the dynamic stress--strain behavior were investigated. The results show that the acicular ferrite dominated microstructure can be obtained for the X70 pipeline steel through rolling processing, and a lot of dislocation cells form in the ferrite laths and the ferrite laths are remarkably fragmentated under the strain rate lower than 2.5$\times$10$^{3}$s$^{-1}$, which leads to the increase in both the strength and the plasticity of the steel.