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研究了镍基合金800H在550℃,25 MPa,600℃,25 MPa和650℃,25 MPa超临界水中的应力腐蚀开裂敏感性,及其在超临界650℃,25 MPa,次临界290℃,15.2 MPa水中的均匀腐蚀性能,同时研究了其在空气中不同温度条件下的机械强度。通过慢应变速率拉伸实验得到相应的应力-应变曲线。结果表明,随着温度的升高,800H的机械强度逐渐下降;SEM像表明800H在这3种工况下均具有应力腐蚀开裂的倾向。由其在空气中不同温度下的机械强度可知,其屈服强度和抗拉强度基本上随温度的升高而降低。800H在超临界水条件下的腐蚀实验表明,其腐蚀增重大致符合抛物线增长规律;而其在次临界条件下的腐蚀却呈现出减重的特征。
The stress corrosion cracking susceptibility of Ni-based alloy 800H in supercritical water at 25 ℃, 550 ℃, 25 MPa, 600 ℃, 25 MPa, 650 ℃ and 25 MPa was investigated. 15.2 MPa water in the uniform corrosion performance, at the same time, its mechanical properties under different temperature conditions in the air. The corresponding stress-strain curves were obtained by slow strain rate tensile test. The results show that with the increase of temperature, the mechanical strength of 800H decreases gradually. The SEM images show that 800H has stress corrosion cracking tendency in these three conditions. From its mechanical strength at different temperatures in the air, its yield strength and tensile strength basically decrease with increasing temperature. The corrosion experiments of 800H under the conditions of supercritical water show that the corrosion weight gain accords with the law of parabola growth, while the corrosion under the subcritical conditions shows the characteristics of weight loss.