锅炉管用Sanicro25奥氏体耐热钢在带压蒸汽中的氧化行为

Oxidation Behavior of Sanicro25 Heat Resistant Austenitic Steel for Boiler Tube in Pressured Steam

在不同温度(650,700℃)和压力为27 MPa的蒸汽中对锅炉管用Sanicro25奥氏体耐热钢进行不同氧化时间(200,500,800,1 300,2 000 h)的氧化试验,研究了试验钢表面及截面形貌、表面物相组成和氧化行为。结果表明:随着温度升高和氧化时间延长,试验钢表面氧化膜的厚度均增大,抗蒸汽氧化性能降低;在不同温度氧化2 000 h后,试验钢表面氧化膜内层为(Ni,Fe)Cr2O4和Cr2O3,外层为Fe3O4,在700℃下内层和外层还分别含有Cr1.3Fe0.7O3和(Ni,Fe)Cr2O4,试验钢表面均生成连续致密的氧化膜。

Steam oxidation tests were conducted on Sanicro25 heat resistant austenitic steel for boiler tube under 27 MPa at different temperatures(650,700℃)for different oxidation times(200,500,800,1 300,2 000 h).The surface and cross section morphology,surface phase composition and oxidation resistance of the test steel were studied.The results show that with the temperature and oxidation time increasing,the thickness of oxide film on the surface of test steel increased,and the steam oxidation resistance decreased.After oxidation at different temperatures for 2 000 h,the inner layer of the oxide film on surface of the test steel was composed of(Ni,Fe)Cr2 O4 and Cr2O3,and the outer layer was composed of Fe3O4;while at 700℃,the inner and outer layers contain Cr1.3Fe0.7O3 and(Ni,Fe)Cr2 O4,respectively.A dense and continuous oxide film was formed on the surface of the test steel.