DD15单晶高温合金900℃的热腐蚀性能  

Hot Corrosion Behavior of DD15 Single Crystal Superalloy at 900℃

作　　者：史振学[1] 刘世忠[1] 赵金乾[1] 王效光[1] 杨万鹏 SHI Zhen-xue;LIU Shi-zhong;ZHAO Jin-qian;WANG Xiao-guang;YANG Wan-peng(Scienee and Technology on Advaneed High Temperature Structural Materials Laboratory,Beijing Institute of Aeron autical Materials,Beijing 100095,China)

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《铸造》2021年第7期828-832,共5页Foundry

基　　金：国防基金项目资助(9140A18040115HK51248)。

摘　　要：在高温度梯度真空定向凝固炉中制备了第四代单晶高温合金DD15,在900℃下研究了DD15单晶高温合金热腐蚀性能。采用扫描电镜、X射线衍射仪、能谱分析仪对腐蚀产物进行了分析。结果表明,DD15合金铸态组织由枝晶组成,枝晶间存在大量共晶组织。合金经过热处理后,获得立方化较好的γ′相组织。腐蚀过程中,腐蚀均匀、无剥落、无腐蚀坑。开始时腐蚀速率稍大,随着时间增加,腐蚀速率逐渐降低。燃气腐蚀条件下,合金100 h的平均腐蚀速率非常低,DD15合金具有优异的热腐蚀性能。腐蚀100 h后产物分为三层,外层为不规则棱形、紧密排列的NiO,中间为混合氧化物,内层为硫化物。内层中有薄片的NiS生成。The fourth generation single crystal superalloy DD15 was cast in the directionally solidified furnace. The hot corrosion behavior at 900 ℃ of the alloy was studied. Morphology of corrosion layer was examined by SEM and their composition was analyzed by XRD and EDS. The results show that the as-cast microstructure of DD15 alloy is composed of dendrites;there is a large amount of eutectic in the indendrite area. The regularly cubical γ′ phase was obtained after heat treatment. In the process of corrosion, the corrosion was uniform without spalling and corrosion pits. The hot corrosion rate at 900 ℃ was relatively higher in initial stage, and then gradually decreased with increasing time. The corrosion speed under the condition of gas corrosion was very slow during the corrosion test of 100 h, thereby DD15 alloy has excellent gas hot corrosion resistance. The corrosion scale is made up of an outer NiO layer, an intermediate layer, mainly composed of oxide mixture, and inner sulfide layer. The flake phase NiS may be formed in someplace of the sulfide layer.

关 键 词：单晶高温合金 DD15 热腐蚀性能 

分 类 号：TG132.32[一般工业技术—材料科学与工程]