摘要
采用光学显微镜、扫描电镜(SEM)和电子探针(EPMA)技术,研究了Mn含量对铸造K325高温合金凝固组织和元素偏析的影响。研究结果表明,Mn元素添加对合金晶粒度和二次枝晶间距无明显影响,却明显促进Nb、Mo元素偏聚于枝晶间,增大合金的偏析倾向。Mn元素的添加,使得Mn元素由正偏析元素变为负偏析元素,但Mn元素对合金铸态组织中第二相析出行为并无明显影响。
The effect of Mn contents on solidification microstructure and segregation of cast K325 alloy were investigated in this paper. The results showed that,Mn element has no significant effect on grain size,secondary dendrite spacing and the second phase precipitation behavior of the alloy. But Mn promotes significantly the segregation of Nb and Mo,atinterdendritic area,and increased segregation tendency of the alloy. The segregation tendency of Mn is from the positive segregation elements into negative segregation elements with the increase of Mn content.
引文
[1]田仲良,包汉生,何西扣,等.700℃汽轮机转子用耐热合金的研究进展[J].钢铁,2015,50(2):54-60.
[2]王天剑,范华,张邦强,等.700℃超超临界汽轮机关键部件用镍基高温合金选材[J].东方汽轮机,2012(2):46-53.
[3]谭梅林,王常帅,郭永安,等.Ti/Al比对GH984G合金长期时效过程中γ'沉淀相粗化行为及拉伸性能的影响[J].金属学报,2014,50(10):1260-1680.
[4]Yun D W,Seo S M,Jeong H W,et al.The effects of the minor alloying elements Al,Si and M n on the cyclic oxidation of Ni-Cr-W-M o alloys[J].Corros.Sci,2014(83):176-188.
[5]Douglass D L,Armijo J S.The effect of silicon and manganese on the oxidation mechanism of Ni-20Cr[J].Oxid Met,1970,2(2):207-231.
[6]Holcomb G R,Alman D E.The effect of manganese additions on the reactive evaporation of chromium in Ni-Cr alloys[J].Scr.M ater,2006,54(10):1821-1825.
[7]Hua B,Kong Y,Zhang W,et al.The effect of Mn on the oxidation behavior and electrical conductivity of Fe-17Cr alloys in solid oxide fuel cell cathode atmosphere[J].J Pow er Sources,2011,196(18):7627-7638.
[8]Holt R T,Wallace W.Impurities and trace elements in nickel-base superalloys[J].Int M ater Rev,1976,21(1):1-24.
[9]郭建亭.高温合金材料学上册[M].北京:科学出版社,2008:184.
[10]魏翔云,杨奇斌.Mn和Si对一种Fe-Ni基高温合金持久缺口敏感性的影响[J].金属学报,1984,20(4):261-265.
[11]材料系高温合金教研室.钛、硅、锰对-种25镍-15铬型铁基高温合金组织和性能的影响[J].东北工学院学报,1979(3):64-73.
[12]邹敏明,张军,刘林,等.熔体超温处理对DD3单晶高温合金二次枝晶间距的影响[J].金属学报,2008,44(2):155-158.
