CAJ | 학술논문

对新型Ni-Cr-W合金在1100℃下不同保温时间下的恒温氧化行为进行了研究.采用扫描电镜(SEM)以及能谱(EDS)对合金热暴露后的表面氧化膜形貌、元素含量以及合金基体的恶化情况进行了分析,表面氧化膜的相组成通过XRD进行确定.结果表明:在氧化初期(<3 h),合金表面生成的单层氧化膜主要由Cr2O3组成,随着氧化时间的延长(>7h),在Cr2O3外逐渐形成了一层具有尖晶石结构的NiCr2O4.一旦外表面被均匀致密的尖晶石膜所覆盖,双层氧化膜NiCr2O4·Cr2O3便能有效的减慢合金基体被进一步氧化.合金亚表层的恶化形式包括晶界的内氧化、空洞以及无碳化物区的形成.合金中高的W含量并没有明显恶化合金的抗氧化性能.
대신형Ni-Cr-W합금재1100℃하불동보온시간하적항온양화행위진행료연구.채용소묘전경(SEM)이급능보(EDS)대합금열폭로후적표면양화막형모、원소함량이급합금기체적악화정황진행료분석,표면양화막적상조성통과XRD진행학정.결과표명:재양화초기(<3 h),합금표면생성적단층양화막주요유Cr2O3조성,수착양화시간적연장(>7h),재Cr2O3외축점형성료일층구유첨정석결구적NiCr2O4.일단외표면피균균치밀적첨정석막소복개,쌍층양화막NiCr2O4·Cr2O3편능유효적감만합금기체피진일보양화.합금아표층적악화형식포괄정계적내양화、공동이급무탄화물구적형성.합금중고적W함량병몰유명현악화합금적항양화성능.
The oxidation process of a newly developed Ni-Cr-W alloy in air at 1100 ℃ has been investigated by varying the holding time. The microstructures and compositions of the surface scale as well as the oxide in cross-section were characterized by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectrum (EDS). The phase identification of the surface scale was carried out using X-ray diffraction (XRD). Results show that in the initial stage of oxidation (<3 h) a single oxidation layer is formed on the alloy. Surface is mainly composed of Cr2O3. With prolonging of oxidation (>7 h), a NiCr2O4 layer with spinel structure grows out gradually in the outer layer of Cr2O3. Once the outer layer of the compact spinel is formed, the double multi-components layer NiCr2O4Cr2O3 will further decelerate the oxidation rate of the ahoy. The degradation of the alloy subsurface includes the inner oxidation of grain boundaries and the formation voids and carbides-free area. The high concentration of W in the alloy does not impair the corrosion resistance of the alloy obviously.