Issue 36

F. Z. Liu et alii, Frattura ed Integrità Strutturale, 36 (2016) 139-150; DOI: 10.3221/IGF-ESIS.36.14 144 Fig. 6 shows the variation of the hydrogen content of the experimental materials in different states along with the changes of tempering temperature. It can be seen that, the content of hydrogen in different states before hydrogen charging were similar; the content of diffusible hydrogen was quite low; except for samples processed at a tempering temperature of 100 °C, the content of non-diffusible hydrogen in samples in different states was highly consistent; the content of hydrogen significantly improved after hydrogen charging, a slight increase in non-diffusible hydrogen and a significantly increase in diffusible hydrogen; as the tempering temperature increased, the content of hydrogen charged reduced (the content of diffusible hydrogen decreased and the content of non-diffusible hydrogen remained unchanged). State of samples Quenching state 100 °C tempering state 200 °C tempering state 400 °C tempering state Samples without hydrogen charging (original state) The content of diffusible hydrogen (ppm) 0.0176 0.0081 0.0009 0.0031 The content of non- diffusible hydrogen (ppm) 0.0741 0.1677 0.0791 0.0834 Total content of hydrogen (ppm) 0.0909 0.1758 0.0801 0.0857 Hydrogen-filled samples The content of diffusible hydrogen(ppm) 0.8629 0.6201 0.5452 0.4441 The content of non- diffusible hydrogen (ppm) 0.1134 0.0951 0.1402 0.1443 Total content of hydrogen (ppm) 0.9771 0.7136 0.6866 0.5882 Table 3 : The content of hydrogen of the experimental materials in different states before and after hydrogen charging (non-bearing, round bar samples). Figure 6 : Vibration of the content of hydrogen of round bar samples in different states before and after hydrogen charging (C d : the content of diffusible hydrogen; Cn: the content of non-diffusible hydrogen; Ct: the content of hydrogen). Hydrogen absorption and effusion behaviors of experimental materials before and after loading The notch tensile samples were loaded for 100 hours in corrosive liquid under critical stress. Then the corroded part was cut down. After surface clearance, it was put into TDS to measure behaviors of hydrogen absorption and effusion, and the measurements results are shown in Tab. 4 and Fig. 8. It can be seen that, the content of hydrogen in samples in four