Effect of W on formation and properties of precipitates in Ni-based superalloys  

作　　者：Zhi-hua Gong Yuan-yuan Ma Han-sheng Bao Gang Yang 

机构地区：[1]Inner Mongolia University of Science and Technology,Baotou 014010,Inner Mongolia,China [2]Institute for Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China

出　　处：《Journal of Iron and Steel Research International》2021年第7期910-919,共10页

基　　金：the National Key Research and Develop Program,China(No.2017YFB0305203).

摘　　要：The formation and properties of precipitates in wrought Ni-based superalloys with different W contents during long-term exposure to high temperatures were investigated.The scanning electron microscope,transmission electron microscope,and chemical phase analysis were used to investigate the formation and properties of precipitates.It is found that with increasing W content,the quantity and thermal stability of MC carbide in Ni-based superalloys increased,while the quantity of M_(23)C_(6)carbides decreased.As the results show,W has a higher partition coefficient in γ'-and γ-matrix,and the addition of W promotes the precipitation of γ'phase.W content has no significant effect on the morphology,size,crystal structure,and coarsening rate of γ'precipitates.The influence of W content on high-temperature tensile and creep properties of the alloys was investigated.The results showed that W content has no obvious influence on the high-temperature yield strength,but the elongation and area reduction decreased significantly when the addition of W was more than 4 wt.%.Because of the similar volume fractions of γ'phase,the creep fracture strengths in the tested alloys with lower W concentrations were not significantly different after long-term exposure at 700℃.

关 键 词：Ni-based superalloy W content Waspaloy alloy Heat resistance MC carbide 

分 类 号：TG146.15[一般工业技术—材料科学与工程]