Effects of hydrogen charging time and prefabricated notches on hydrogen embrittlement susceptibility of a GPa-level marine steel
The relationship between the hydrogen embrittlement sensitivity of a GPa-level marine steel and the hydrogen charging time,the pre-fabricated notches was studied.The hydrogen charging current density was set to 10mA/cm2.The hydrogen charging time was set to 2,6 and 24 h,respectively.V-shaped and arc-shaped notches were pre-fabricated on the parallel sections of the tensile specimen.In addition,scanning electron microscopy analysis was performed on the fracture morphology.Experimental results show that the hydrogen charging time has a significant impact on the hydrogen embrittlement susceptibility of the studied steel.The longer the hydrogen charging time,the worse the plasticity of the material and the higher the hydrogen embrittlement susceptibility index.Once the hydrogen charging time is longer than 6 h,the increasing rate of the hydrogen embrittlement sensitivity index slows down and tends to a constant value;the hydrogen embrittlement sensitivity index and fracture surface morphology of the arc-shaped notched specimen are similar to those of the unnotched specimen,and can be used for hydrogen embrittlement susceptibility analysis.However,due to the large stress concentration,the V-notched specimen has a great plasticity loss after 6 h of hydrogen charging,and the fracture morphology is significantly different from that of the unnotched specimen.V-notch is not suitable for hydrogen embrittlement susceptibility analysis.
NETL
NSTL
万方数据
