(1. 沈陽(yáng)工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，沈陽(yáng) 110870；
2. 沈陽(yáng)理工大學(xué) 裝備工程學(xué)院，沈陽(yáng) 110159)
摘 要: 通過(guò)對(duì)鎳基合金進(jìn)行不同溫度的恒溫氧化試驗(yàn)、橫斷面的組織形貌觀察及微區(qū)成分分析，研究一種高Cr鎳基合金在恒溫氧化期間的氧化物分布特征、內(nèi)氧化及內(nèi)氮化行為。結(jié)果表明：該高Cr 鎳基合金在850、900、950和1 000 ℃空氣中氧化100 h期間，合金表層發(fā)生元素的外氧化，且在外氧化膜中出現(xiàn)分層結(jié)構(gòu)，由表及里各層中的主要氧化物分別為Al2O3、Cr2O3、NiCr2O4和NiAl2O4、Cr2O3、CrTaO4和Al2O3；合金在900 ℃以下為完全抗氧化級(jí)，900~1 000 ℃為抗氧化級(jí)。該合金在各溫度的恒溫氧化期間，均發(fā)生元素Al的內(nèi)氧化和內(nèi)氮化；與外氧化膜相鄰的區(qū)域?yàn)樵谹l的內(nèi)氧化區(qū)，遠(yuǎn)離外氧化膜的基體內(nèi)部形成元素Al的內(nèi)氮化區(qū)；隨恒溫氧化溫度的升高，內(nèi)氧化區(qū)和內(nèi)氮化區(qū)的深度增加，內(nèi)氧化物和內(nèi)氮化物的尺寸增大。其中，在內(nèi)氧化物、內(nèi)氮化物周圍形成元素Al的貧化區(qū)，在貧化區(qū)內(nèi)發(fā)生g ′相的分解及貧乏。
關(guān)鍵字: 鎳基合金；恒溫氧化；動(dòng)力學(xué)曲線；內(nèi)氧化；內(nèi)氮化
high Cr contents during high temperature exposure
（1. School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110178, China;
2. Equipment Engineering College, Shenyang Ligong University, Shenyang 110159, China）
Abstract:By mean of the microstructure observation and composition analysis of the isothermal oxidation layers, the internal oxidation and internal nitridation behavior of the nickel-base superalloy with high Cr contents were investigated. The results show that the surface layer oxidation occurs during thermal exposure of the alloy at 850, 900, 950 and 1 000 ℃, and the layer structure appears in the oxidation films, thereinto, the main oxides in the layers from surface to inside, in turn, are identified as Al2O3, Cr2O3, NiCr2O4 and NiAl2O4, Cr2O3, CrTaO4 and Al2O3, respectively. The oxidation behavior of the alloy under 900 ℃ is determined as the fully oxidation resistance level, the oxidation behaviors of the alloy in the ranges of 900−1 000 ℃ are determined as the oxidation resistance level. The internal oxidation of the element Al occurs during the isothermal oxidization of the alloy at different temperatures. The regions near the surface oxides of the surface oxides is identified as the internal oxidizing zone of the element Al, and the matrix region far from the layer of the surface oxides is identified as the internal nitridizing zone of the element Al. And the depths of the internal oxidization, nitridizing zone and the size of the internal oxides, nitrides increase with enhancing the temperature of the isothermal oxidization. Thereinto, the poor-zone of the element Al appears in the around region near the oxides and nitrides, and the decomposition and scarceness of the g ′ phase occur within the poor-zone of the element Al.
Key words: Ni-base superalloy; isothermal oxidation; kinetics curves; internal oxidation; internal nitridation
