超(超)临界锅炉用18-8系奥氏体不锈钢阶段式氧化动力学特征研究  

Staged Feature of Oxidation Kinetics of 18-8Cr Austenitic Stainless Steel for Ultra-supercritical Boiler Application

作　　者：周永莉[1] 鲁金涛[1] 李浩[1,2] 杨珍[1] 党莹樱[1] 赵新宝[1] 袁勇[1] ZHOU Yongli;LU Jintao;LI Hao;YANG Zhen;DANG Yingying;ZHAO Xinbao;YUAN Yong(Xi'an Thermal Power Research Institute Co., Ltd., Xi'an 710032;College of Mechanical & Electrical Engineering, Shaanxi University of Science & Technology, Xi'an 712000)

机构地区：[1]西安热工研究院有限公司,西安710032 [2]陕西科技大学机电工程学院,西安712000

出　　处：《材料导报》2018年第A02期389-393,共5页Materials Reports

基　　金：国家自然科学基金(51401163;51401164);华能集团科技项目(HNKJ18-H15)

摘　　要：本工作利用动态饱和蒸汽氧化实验平台,研究了两种典型组织特征的18-8奥氏体不锈钢在600℃饱和蒸汽环境中的氧化行为。结果表明:Super304H和TP347H合金的氧化动力学均遵循阶段式抛物线规律,且第二阶段的氧化速率均高于第一阶段,瘤状氧化物及内氧化是导致阶段式氧化动力学特征的主要原因。合金表面氧化膜呈两种典型特征:一种为疏松瘤状氧化物Fe3O4,与试样表面氧化膜下方内氧化物FeCr2O4呈双层结构,该结构特征减小了(Cr,Mn)2O_3的比表面积,从而使氧化激活能降低、氧化速率增大;另一种为平整(Cr,Mn)2O_3氧化膜。内氧化物沿晶界长大形成富Cr氧化物,厚度为1～2个晶粒大小,且按照晶粒取向生长。This work investigated the oxidation behavior of two typical 18-8Cr Austenitic stainless steel at 600℃by dynamic saturated steam.The results showed that the oxidation kinetic of Super304H and TP347H alloy followed the laws of the staged parabolic((ΔW/A)2=k p t),and the k p of second stage was higher than that of the first stage,which was mainly because the emergence of nodular oxide and internal oxidation.Two kinds of typical morphologies on the alloy surface were observed,the first one was a duplex oxide,the outer layer with loosen nodular-typed was Fe 3O 4,and the inner oxides was FeCr 2O 4,which decreased specific surface area of protecting(Cr,Mn)2O3 oxide,thus reduced the oxidation activation energy and increased oxidation rate.The other one was a smooth and thin oxide film,which was mainly consisted of(Cr,Mn)2O3.The inner chromium rich oxide was also around the periphery of the grains,and influenced by the orientation and size of alloy grains,also the thickness has penetrated the metal by 1-2 grains.

关 键 词：18-8系奥氏体钢 晶粒度 蒸汽氧化 动力学 阶段式 

分 类 号：TG178[金属学及工艺—金属表面处理]