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以慢速率拉伸试验来评估硫化应力腐蚀,对於时效PH13-8Mo不锈钢,其缺口拉伸强度(NTS)以及拉伸破坏特征的影响,实验并利用电化学渗透方法来测定不同显微组织其氢扩散速率、氢通量以及视固溶量。实验结果显示:所有时效试片对於硫化应力腐蚀皆展现出高程度敏感性。氢渗透结果指出,H800、H900以及H1000时效试片具有极为相近的氢渗特性,然而相对於其他试片,H1100试片却表现出较低的氢扩散率、氢通量以及较高的固溶量。当试片时效温度低於1000°F时,类同的氢渗性质导致不同试片具有相同程度的氢脆敏感性,而H1100试片显现相对较低的氢脆性。当试片时效温度低於1000°F时,氢被捕集在基地中而呈现準劈裂破坏的特征。此外,在H1100试片中由於存在着晶界沃斯田铁,氢趨向於沿着晶界扩散并被捕集,造成试片在应变过程中产生了些许沿晶破坏。
The effects of sulfur stress corrosion on the aged PH13-8Mo stainless steel, its notched tensile strength (NTS) and the tensile failure characteristics were evaluated by a slow rate tensile test. The electrochemical penetration method was used to determine the effect of different microstructures The hydrogen diffusion rate, hydrogen flux and volume of solution. Experimental results show that all aged specimens exhibit a high degree of sensitivity to stress corrosion cracking. Hydrogen permeation results indicate that H800, H900, and H1000 aged specimens have very similar hydrogen permeation properties, whereas H1100 specimens exhibit lower hydrogen diffusivity, higher hydrogen flux, and higher solution than the other specimens the amount. Similar hydrogen permeation properties lead to the same degree of hydrogen embrittlement sensitivity for different test pieces when the test piece aging temperature is below 1000 ° F, whereas H1100 test pieces show a relatively low hydrogen embrittlement. Hydrogen is trapped in the base and exhibits quasi- fracturability when the specimen aging temperature is below 1000 ° F. In addition, due to the presence of grain boundary ferritic in H1100, hydrogen tends to diffuse along the grain boundaries and be trapped, resulting in some damage to the specimen during the strain.