材料期刊网

采用增重法研究了新型奥氏体耐热钢NH4在700℃、900℃和1000℃空气中高温氧化动力学，并结合X射线衍射（XRD）、扫描电镜（SEM）及能谱分析（EDX）等手段，对各温度下的氧化膜的形貌和成分进行了研究。结果发现，NH4钢在700℃、900℃和1000℃时的平均氧化速率分别为：0.064 g/(m2 h)、0.083 g/(m2 h)和0.2786 g/(m2 h)。在700℃和900℃时的氧化层是由外层的Cr2O3和内层的SiO2、Al2O3组成，在1000℃时是由Cr、Si和Al三种元素的混合氧化物组成。高温下SiO2先于Cr2O3形成，且SiO2对Cr2O3的生长有促进作用。

The high-temperature oxidation resistance of new austenitic stainless steel NH4 in air over the temperature range of 700℃～1000℃ was studied by using the way of gain weight. The surface morphology、constituent and micro-structure of the oxidation scale was analyzed by using XRD、SEM and EDX techniques. Experimental result indicated that the average oxidation speed of NH4 were 0.064 g/(m2 h)(700℃),0.083 g/(m2 h)(900℃)and0.2786 g/(m2 h)(1000℃).The compositions of oxide included outer Cr2O3 film and inner SiO2 film at 700℃ and 900℃. While at 1000℃ the oxide layer was a mixture of Cr2O3、SiO2 and Al2O3. At high temperature SiO2 layer was formed before Cr2O3 layer, and SiO2 layer was in favor of the formation of Cr2O3 layer.