The vacuum vessel is the core component of the China future fusion engineering test reactor. Port stub is a part of vacuum vessel and it is welded by electron beam welding (EBW), which has capability to weld more than 50 mm thickness stainless steel by a single pass. In order to explore non-uniform properties of EB welded joint, beam oscillation was applied during the welding process and the microstructure and microhardness of 50 mm 316L austenitic stainless steel welded joint were analyzed. The results showed that the weld microstructure was composed of austenite and ferrite. From the upper layer near the center line of the weld to the lower layer, the microstructure changed from coarse lathy/skeletal ferrite to more close-packed skeletal ferrite and equiaxed gain. Welded joints with beam oscillation appeared equiaxed gain earlier in the weld thickness direction. Beam oscillation can improve the quality of the welds surface forming. The microhardness of the welds gradually increased from the upper layer to the lower layer.
XIA Xiaowei
,
WU Jiefeng
,
LIU Zhihong
,
SHEN Xu
. Study on non-uniform properties of 316L thick plate joint using electron beam welding in port stub of vacuum vessel[J]. Transactions of The China Welding Institution, 2019
, 40(9)
: 53
-58
.
DOI: 10.12073/j.hjxb.2019400235
[1] 修磊,吴杰峰,刘志宏,等.大型真空室焊接部件焊接变形预测与控制方法[J].焊接学报, 2017, 38(12):51-56 Xiu Lei, Wu Jiefeng, Liu Zhihong, et al. Welding deformation prediction of large heavy-load complex contour vacuum vessel welded component and study on control method[J]. Transactions of the China Welding institution, 2017, 38(12):51-56
[2] 陈倩倩,李东,贺聪聪,等.大厚度电子束焊接接头厚度方向的组织差异性[J].焊接学报, 2015, 36(9):79-82 Chen Qianqian, Li Dong, He Congcong, et al. Microstructure difference analysis of large thickness welded joint with EBW[J]. Transactions of the China Welding institution, 2015, 36(9):79-82
[3] Wang T, Li N, Zhang Y, et al. Influence of welding speed on microstructures and mechanical properties of vacuum electron beam welded TZM alloy joints[J]. Vacuum, 2018, 149:29-35.
[4] Kar J, Roy S K, Roy G G, et al. Effect of beam oscillation on microstructure and mechanical properties of AISI 316L electron beam welds[J]. Metallurgical&Materials Transactions A, 2017, 48(4):1759-1770.
[5] Alali M, Todd I, Wynne B P, et al. Through-thickness microstructure and mechanical properties of electron beam welded 20mm thick AISI 316L austenitic stainless steel[J]. Materials&Design, 2017, 130:488-500.
[6] Elmer J W, Allen S M, Eagar T W, et al. Microstructural development during solidification of stainless steel alloys[J]. Metallurgical Transactions A, 1989, 20(10):2117-2131.
[7] Kar J, Roy S K, Roy G G. Influence of beam oscillation in electron beam welding of Ti-6AL-4V[J]. The International Journal of Advanced Manufacturing Technology, 2018, 94(9-12):4531-4541.
[8] Fu P F, Mao Z Y, Zuo C J, et al. Microstructures and fatigue properties of electron beam welds with beam oscillation for heavy section TC4-DT alloy[J]. Chinese Journal of Aeronautics, 2014, 27(04):1015-1021.
[9] European Committee for Standardization. EN ISO17639:2013. Destructive tests on welds in metallic materials-macroscopic and microscopic examination of welds[S]. 2013.
[10] Wang H, Hamed Mohamed S, Shankar S. Interaction between primary dendrite arm spacing and velocity of fluid flow during solidification of Al-Si binary alloys[J]. Journal of Materials Science, 2018, 53(13):9771-9789.
[11] Zuma B N, Merwe J W V D. Effect of Ru addition on the mechanical properties and microstructure of 316l austenitic stainless steel weld metal[J]. Procedia Manufacturing, 2016, 7:2-7.
[12] John C L, Damian J K. Welding metallurgy and weldability of stainless[M]. New York:John Wiley&Sons Inc, 2005.
[13] Yin H, Felicelli S D. Dendrite growth simulation during solidification in the LENS process[J]. Acta Materialia, 2010, 58(4):1455-1465.
[14] Kar J, Roy S K, Roy G G. Effect of beam oscillation on microstructure and mechanical properties of AISI 316L electron beam welds[J]. Metallurgical and Materials Transactions A, 2017, 48(4):1759-1770.
[15] Hsieh C C, Guo X, Chang C M, et al. Dendrite evolution of delta (δ) ferrite and precipitation behavior of sigma (σ) phase during multipass dissimilar stainless steels welding[J]. Metals&Materials International, 2010, 16(3):349-356.