中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2015年
6期
1490-1497
,共8页
谢君%于金江%孙晓峰%金涛
謝君%于金江%孫曉峰%金濤
사군%우금강%손효봉%금도
K416B镍基合金%显微组织%蠕变行为%断裂机制
K416B鎳基閤金%顯微組織%蠕變行為%斷裂機製
K416B얼기합금%현미조직%연변행위%단렬궤제
K416B Ni-based superalloy%microstructure%creep behavior%fracture mechanism
通过组织形貌观察和蠕变性能测试,研究了含铪高钨K416B镍基铸造合金的组织及蠕变机制。结果表明:合金铸态组织由γ基体、γ′相、MC和M 6 C型碳化物组成;其中,MC碳化物主要以链状和汉字型结构分别在晶界和枝晶间析出,而大块状M6C碳化物镶嵌在共晶处;蠕变期间,合金的变形机制是位错在基体中可沿不同方向发生滑移,且位错可绕过或剪切γ′相;蠕变后期,高密度位错在碳化物和晶界处塞积,产生应力集中,致使裂纹沿晶界和碳化物/共晶界面处萌生及扩展是合金的断裂机制。
通過組織形貌觀察和蠕變性能測試,研究瞭含鉿高鎢K416B鎳基鑄造閤金的組織及蠕變機製。結果錶明:閤金鑄態組織由γ基體、γ′相、MC和M 6 C型碳化物組成;其中,MC碳化物主要以鏈狀和漢字型結構分彆在晶界和枝晶間析齣,而大塊狀M6C碳化物鑲嵌在共晶處;蠕變期間,閤金的變形機製是位錯在基體中可沿不同方嚮髮生滑移,且位錯可繞過或剪切γ′相;蠕變後期,高密度位錯在碳化物和晶界處塞積,產生應力集中,緻使裂紋沿晶界和碳化物/共晶界麵處萌生及擴展是閤金的斷裂機製。
통과조직형모관찰화연변성능측시,연구료함협고오K416B얼기주조합금적조직급연변궤제。결과표명:합금주태조직유γ기체、γ′상、MC화M 6 C형탄화물조성;기중,MC탄화물주요이련상화한자형결구분별재정계화지정간석출,이대괴상M6C탄화물양감재공정처;연변기간,합금적변형궤제시위착재기체중가연불동방향발생활이,차위착가요과혹전절γ′상;연변후기,고밀도위착재탄화물화정계처새적,산생응력집중,치사렬문연정계화탄화물/공정계면처맹생급확전시합금적단렬궤제。
By means of microstructure observation and creep property measurement, the microstructure and creep mechanism of Hf-containing K416B as-cast Ni-based superalloy with high W content were investigated. The results show that the as-cast microstructure of the alloy consists of γ matrix, γ′ phase, MC and M 6 C carbides. Thereinto, the MC carbide with chain-like structure and Chinese script precipitates, in the grain boundaries and inter-dendrite, respectively. And the blocky M 6 C carbide embeds in the eutectic. During creep, the deformation mechanisms of the alloy are that the dislocations with different orientations slip in the matrix, and the dislocation may bypass or shear intoγ′phase. In the late stage of creep, high density dislocations may pile up near the carbides or boundaries, and the fact may induce the stress concentration to cause the crack initiating and propagating along the grain boundaries and the interface between the carbide and eutectic, which is considered to be the fracture mechanism of the alloy.