Alumina-Forming Austenitic Alloys for Advanced Recuperators
Alumina-Forming Austenitic Alloys for Advanced Recuperators
复制标题
用于高级换热器的氧化铝成型奥氏体合金
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
P. Maziasz
中科院分区：
文献类型：
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作者：
B. Pint;J. Shingledecker;M. Brady;P. Maziasz
在过去的十年中，薄壁换热器的材料选择得到了广泛的研究。在最新一代回热式涡轮机发动机中，347型不锈钢已被高合金钢和镍基氧化铬形成合金所取代。然而，废气中氧化铬蒸发的高（线性）速率从根本上限制了这些氧化铬形成合金的氧化寿命。一种解决方案是使用对这种环境更具抵抗力的氧化铝形成合金。较低的规模增长动力学和水蒸气存在下的蒸发阻力表明，氧化铝形成合金的寿命增加了一个数量级。这种策略的一个显著问题是，添加足够的Al以形成外部氧化铝氧化皮会导致蠕变强度大幅下降。然而，已经开发了新的铁基奥氏体组合物，其具有足够的强度用于700 ℃以上的这种应用。
Materials selection for thin-walled recuperators has been extensively investigated over the past decade. In the latest generation of recuperated turbine engines, type 347 stainless steel has been replaced by higher alloyed steels and Ni-base chromia-forming alloys. However, high (linear) rates of chromia evaporation in exhaust gas fundamentally limits the oxidation lifetime of these chromia-forming alloys. One solution is to use alumina-forming alloys that are more resistant to this environment. The lower scale growth kinetics and resistance to evaporation in the presence of water vapor suggests an order of magnitude increase in lifetime for alumina-forming alloys. A significant problem with this strategy was the large drop in creep strength with the addition of sufficient Al to form an external alumina scale. However, new Fe-base austenitic compositions have been developed with sufficient strength for this application above 700 C.