新一代新型抗高温氧化奥氏体耐热钢的研究进展

摘要

This paper introduces a new class of high-temperature oxidation-resistant austenitic heat-resistant steels which offer a continuous, stable, spontaneous dense layer of alumina with superior high-temperature oxidation resistance and creep resistance to conventional chromia（ Cr2O3 ）-forming stainless steels. Detailed analyses of the oxidation mechanisms and alloying effects on the oxidation behavior of these newly developed alumina-forming steels at high temperatures in air with 10% water vapor were presented. It was also found that the creep resistance and high-temperature mechanical properties for these heat-resistant austenitic steels were improved due to precipitations of stable nanosized NbC , Fe2Nb and NiAl precipitates at elevated temperatures. The perspective of utilizing these novel alumina-forming austenitic stainless steels as engineering components is analyzed and discussed.%新一代奥氏体耐热钢在氧化过程中自发形成连续、稳定、致密的氧化铝层，与传统的在金属表面形成Cr2O3保护层的不锈钢相比，具有更优异的高温抗氧化性能和良好的抗蠕变能力。详细地分析了新型抗高温氧化奥氏体耐热钢的抗氧化机理，并且探讨了一些合金元素对新型奥氏体耐热钢在高温含10％水蒸气的气氛中抗氧化性能的影响。指出新一代奥氏体耐热钢在氧化过程中形成稳定的纳米级沉淀相NbC，以及在高温时形成的稳定Fe2Nh和NiAl沉淀相，有力地改善了其抗蠕变性能和高温力学性能。最后展望了这类以Al2O3为抗氧化层的新型奥氏体耐热钢的应用前景。