CAJ | 학술논문

采用慢拉伸试验研究了AL‐6XN合金在550～650℃、25 M Pa超临界水中的应力腐蚀行为，使用扫描电镜观察了材料断口形貌与标距面裂纹分布。结果显示：550℃试验条件下材料表现为穿晶开裂，标距面裂纹很多且分布较均匀，试样边角处出现扇形河流花样；650℃试验条件下材料表现为沿晶开裂，断口呈现典型的冰糖状，标距面裂纹数量大幅减少且集中于断口附近，相应的延伸率和断面收缩率也大幅降低。质子辐照对AL‐6XN宏观力学性能影响不大，但导致试样断口的扇形花样（起裂源）数量增加，解理台阶宽度增大。以上结果表明，AL‐6XN在超临界工况下具有严重的应力腐蚀开裂敏感性，升高温度和质子辐照会明显提高材料的应力腐蚀敏感性。
채용만랍신시험연구료AL‐6XN합금재550～650℃、25 M Pa초림계수중적응력부식행위，사용소묘전경관찰료재료단구형모여표거면렬문분포。결과현시：550℃시험조건하재료표현위천정개렬，표거면렬문흔다차분포교균균，시양변각처출현선형하류화양；650℃시험조건하재료표현위연정개렬，단구정현전형적빙당상，표거면렬문수량대폭감소차집중우단구부근，상응적연신솔화단면수축솔야대폭강저。질자복조대AL‐6XN굉관역학성능영향불대，단도치시양단구적선형화양（기렬원）수량증가，해리태계관도증대。이상결과표명，AL‐6XN재초림계공황하구유엄중적응력부식개렬민감성，승고온도화질자복조회명현제고재료적응력부식민감성。
The stress corrosion cracking (SCC) behavior of AL‐6XN alloy in supercriti‐cal water with 550‐650 ℃ and 25 MPa was studied by slow strain rate test (SSRT) .The facture morphology and gauge surface crack of the specimen were observed by scanning electron microscopy (SEM ) .In 550 ℃ test condition ,the material presents transgranu‐lar cracking .Many uniform distributed cracks appear on the gauge surface ,and fan‐shaped river patterns appear at the corners on the fracture surface .In 650 ℃ test condi‐tion ,the material displays intergranular cracking .The fracture surface reveals typical rock candy pattern ,and much fewer cracks appear at the fracture end on the gauge sur‐face .Proton irradiation at 550 ℃ has little effect on the mechanical property of AL‐6XN ,but induces more fan‐shaped patterns (cracking origins) and wider slipping steps . AL‐6XN alloy presents severe SCC sensitivity in supercritical water ,which is enhanced by higher temperature and proton irradiation .