摘要
利用光学显微镜、扫描电子显微镜、电子探针和X射线衍射等研究了Zr对一种铸造镍基高温合金一次碳化物和性能的影响。结果表明,添加Zr使铸造镍基高温合金中的一次MC碳化物形貌和分布发生明显变化。随Zr含量增加,晶粒内的骨架状碳化物减少,分布在晶界上的碳化物相应增多。碳化物形貌也由片状或针状向比较孤立的块状转变。能谱分析表明,片状碳化物含Zr量低,主要成分为Nb和C,而块状碳化物几乎有半数的Nb为Zr所替代。掺杂了Zr的MC碳化物晶格常数变大。合金的1 100℃/40 MPa条件下持久寿命随Zr含量增加,先增加,后减少,在Zr含量为0.049%时合金达到最大寿命77.8 h。在1 000℃时合金的抗拉强度随着Zr含量增加而缓慢地增加,且伸长率也相应提高。
Optical microscope, scanning electron microscope, electron probe micro analysis and X-ray diffraction were employed to researching the influence of Zr on the primary carbide and property of cast superalloy. The results show that the additions Zr change the morphology and distribution of MC carbide remarkably. With the increasing Zr content, the intragranular carbide decreases, while the carbide around the grain boundary increases. And the morphologies of carbide transfer from platelet-like and needle-like to discontinuous blocky-like. EDS analysis shows that the carbide in platelet-like contains low Zr element, the dominant composition is Nb and C, while nearly half of Nb is substituted by Zr in blocky carbide. The lattice parameter of MC carbide rises if doped with Zr. The creep rupture life of the alloy at 1 100 ℃/40 MPa increases with increasing Zr content first, then decreases, the peak life is 77.8 h when Zr concentration reaches 0.049%. The tensile strength rises slowly with the increment of Zr, and the elongation also improves.
出处
《铸造》
CAS
CSCD
北大核心
2012年第10期1177-1180,1185,共5页
Foundry
关键词
锆
镍基高温合金
碳化物
持久寿命
Zr
Ni-based superalloy
carbide
creep rupture life
