当前位置: X-MOL 学术Int. J. Miner. Metall. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Investigation of secondary phases and tensile strength of nitrogen-containing Alloy 718 weldment
International Journal of Minerals, Metallurgy and Materials ( IF 4.8 ) Pub Date : 2020-09-05 , DOI: 10.1007/s12613-020-2013-4
Behrooz Nabavi , Massoud Goodarzi , Abdul Khaliq Khan

The influence of nitrogen content on the precipitation of secondary phases and the tensile strength of Alloy 718 during gas tungsten arc welding was investigated. Various types of precipitates were characterized using scanning electron microscopy and transmission electron microscopy. The results showed that in the fusion zone, the volume fraction of Nb-rich phases such as Laves, (Nb,Ti)C, and δ phases, as well as Ti-rich phases such as (Ti,Nb)CN and (Ti,Nb)N, increased with increase in the nitrogen content due to the microsegregation of Nb and Ti within interdendritic areas. Nitrogen was also found to decrease the size of γ″ particles within γ dendrites. For precipitates in the partially melted zone, constitutional liquation was observed for both (Nb,Ti)C and (Ti,Nb)N particles. Based on the results of tensile tests, the weld containing 0.015wt% nitrogen exhibited the highest ultimate tensile strength (UTS), whereas more addition of nitrogen led to a decrease in both the UTS and yield strength due to the increased content of brittle Laves phases and decreased size of γ″.



中文翻译:

含氮718合金焊件的第二相和拉伸强度的研究

研究了氮气含量对钨极氩弧焊过程中二次相的析出和718合金拉伸强度的影响。使用扫描电子显微镜和透射电子显微镜对各种类型的沉淀物进行表征。结果表明,在熔合区,富Nb相如Laves,(Nb,Ti)C和δ相以及富Ti相如(Ti,Nb)CN和(Ti ,Nb)N随着氮含量的增加而增加,这是由于Nb和Ti在枝晶间区域内的微偏析所致。还发现氮减少了γγ ''颗粒的尺寸树突。对于部分熔融区域中的沉淀物,对于(Nb,Ti)C和(Ti,Nb)N颗粒均观察到组成液化。根据拉伸试验的结果,含0.015wt%氮的焊缝具有最高的极限抗拉强度(UTS),而更多的氮添加会导致UTS和屈服强度均降低,这是由于脆性拉夫斯相的含量增加了并减小了γ ″的大小。

更新日期:2020-09-06
down
wechat
bug