Relationship between Oxide Inclusion and Changing Rule of Low Experimental Temperature Impact Toughness of Ni-Cr-Mo-V Steel Weld Metal

被引:0
|
作者
Wang C. [1 ]
Tong Z. [1 ]
Zhang C. [1 ]
Yang X. [2 ]
Ning G. [1 ]
Yang W. [1 ]
机构
[1] China Institute of Atomic Energy, P.O. Box 275-51, Beijing
[2] Jiangsu Nuclear Power Corporation, Lianyungang
来源
Yuanzineng Kexue Jishu/Atomic Energy Science and Technology | 2018年 / 52卷 / 04期
关键词
Fracture failure mechanism; Impact toughness; Oxide inclusion; Reactor pressure vessel; Weld;
D O I
10.7538/yzk.2017.youxian.0682
中图分类号
学科分类号
摘要
The Charpy impact tests of Ni-Cr-Mo-V steel used as reactor pressure vessel material weld metal were performed, and the result of the impact experiments shows that at low experimental temperature, the impact toughness of weld metal is worse gradually at the same experimental temperature along the direction from cosmetic welding to weld root. The spherical oxide inclusions with a diameter of 0.3-2.0 μm, located at the crack initiation site, dimples and cleavage facet initiation, were observed at the low temperature experimental fracture. In the process, the oxide inclusions and matrix separate to form microcracks, and develop into crack initiation site, dimples and cleavage facet initiation. It is concluded that the oxide inclusions are the main reason for low temperature failure of the weld. At the same time, the amount of oxide inclusions along the cosmetic welding to the weld root increases gradually, which causes the increase of the microcracks nucleation rate, and then the low temperature impact toughness of the weld is worse gradually along the direction from cosmetic welding to weld root. © 2018, Editorial Board of Atomic Energy Science and Technology. All right reserved.
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页码:691 / 698
页数:7
相关论文
共 13 条
  • [1] Margolin B.Z., Nikolayev V.A., Yurchenko E.V., Et al., Analysis of embrittlement of WWER-1000 RPV materials, International Journal of Pressure Vessels and Piping, 89, pp. 178-186, (2012)
  • [2] Lau T., Weatherly G.C., Mclean A., The sources of oxygen and nitrogen contamination in submerged arc welding using CaO-Al<sub>2</sub>O<sub>3</sub> based fluxes, Welding Journal, 64, 12, pp. 343-347, (1985)
  • [3] North T.H., Bell H.B., Nowicki A., Et al., Slag/metal interaction, oxygen and toughness in submerged arc welding, Welding Journal, 57, 3, pp. 63-67, (1978)
  • [4] Tong Z., Cui Z., Zhao J., Et al., Thermal ageing assessment of RPV in VVER-1000 reactor, Atomic Energy Science and Technology, 49, 5, pp. 903-908, (2015)
  • [5] GOST 9454-78 Test method for testing the impact strength at low, room and high temperature, Moscow: Izd Standartov, (1985)
  • [6] Xue Q., Liu D., Yin C., Et al., Influence of M-A constituent on microstructure and impact property of weld metal of X70 pipeline steel, Heat Treatment of Metals, 38, 8, pp. 32-37, (2013)
  • [7] Li X., Shang C., Han C., Et al., Influence of necklace-type M-A constituent on impact toughness and fracture mechanism in the heat affected zone of X100 pipeline steel, Acta Metallurgica Sinica, 52, 9, pp. 1025-1035, (2016)
  • [8] Zhu J., Ye L., Gao N., Et al., The immediate cause presenting low impact values in cold-state temperature for multilayer weld of carbon steel, Journal of South China University of Technology: Natural Science Edition, 22, 1, pp. 88-99, (1994)
  • [9] Thompson A.W., Knott J.F., Micromechanisms of brittle fracture, Metallurgical and Materials Transactions A, 24, 3, pp. 523-534, (1993)
  • [10] Curry D.A., Cleavage micromechanisms of crack extension in steels, Metal Science, 14, 8-9, pp. 319-326, (1980)