Study of temperature effect on hydrogen embrittlement in X70 pipeline steel
Xiao Xing, Zhiwen Pang, Hao Zhang, Jianguo Liu, Gan Cui
Abstract
The study investigates the temperature effect on hydrogen embrittlement (HE) in X70 steel using Devanathan-Stachurski and tensile tests under varying cathodic hydrogen-charging currents. The most severe HE temperature threshold is identified via scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) methods. The temperature thresholds for 10 mA/cm2 and 20 mA/cm2 are 293 K and 283 K, respectively, while no critical temperature at 30 mA/cm2. The underlying mechanism is studied, and a predictive model is established. Also, the primary hydrogen-induced fracture plane is identified as {110}, beneath where hydrogen enhances plastic deformation in {110}<111> and inhibits in {112}<111>.