摘要
采用增重法研究了441铁素体不锈钢在模拟汽车废气环境中于900~1050℃范围内的氧化行为。运用XRD、SEM以及EDS技术分析了试样表面氧化膜的形貌和结构特征。结果表明,441铁素体不锈钢在汽车废气环境中的上限服役温度在900℃左右,该温度下形成的氧化膜为双层结构,外层的Mn-Cr尖晶石层和内部的Cr2O3层。当氧化温度升到950℃及以上时,氧化膜上出现瘤状氧化物,氧化物瘤沿初期Mn-Cr尖晶石层两侧分布,外部主要是铁的氧化物,内部为铁铬氧化物。氧化温度达到1050℃时,氧化物瘤内部会形成较多空隙。氧化物瘤的生长导致发生失稳氧化,并使氧化动力学从抛物线规律转变为直线规律。
The oxidation behavior of type 441 ferritic stainless steel in a synthetic automotive exhaust gas at 900~1050 ℃ was studied by means of mass change measurement, XRD, SEM and EDS. The results indicate that the oxide scale formed at 900 ℃ has a bi-layered structure, i.e., an outer Mn-Cr spinel layer and an inner Cr2O3 layer, while the temperature 900 ℃ is known as the upper service limit for the type 441 ferritic stainless steel in automotive. When the oxidation temperature increases to 950 ℃ and above, oxide nodules appears on the oxide scale. A nodule usually can be differentiated into two parts by the initial formed Mn-Cr spinel layer, Fe-oxides and Fe-Cr oxides mainly form on top of and beneath the spinel thin layer respectively. When the oxidation temperature reaches 1050 ℃, many voids form in the oxide nodules. The growth of oxide nodules leads to breakaway oxidation, therewith, changes the oxidation kinetics from parabolic to linear.
作者
陈以生
詹建明
倪清钊
李谋成
Yisheng CHEN;Jianming ZHAN;Qingzhao NI;Moucheng LI(Materials Science Institute of Shanghai University, Shanghai University, Shanghai 200072, China;Materials Genome Institute of Shanghai University, Shanghai University, Shanghai 200444, China)
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2019年第2期174-180,共7页
Corrosion Science and Protection Technology
基金
国家自然科学基金(U1660205)~~
关键词
铁素体不锈钢
高温氧化
汽车废气
失稳氧化
ferritic stain less steel
high temperature oxidati on
automotive exhaust gas
breakaway oxidati on
