Study on fatigue property and microstructure characteristics of welded nuclear power rotor with heavy section
Study on fatigue property and microstructure characteristics of welded nuclear power rotor with heavy section
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DOI：
10.1016/j.jallcom.2013.09.048
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发表时间：
2014-01
影响因子：
6.2
通讯作者：
Liu Peng;F. Lu;Xia Liu;Hui-jun Ji;Yulai Gao
中科院分区：
文献类型：
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作者：
Liu Peng;F. Lu;Xia Liu;Hui-jun Ji;Yulai Gao
系统地研究了核电大截面转子焊接接头的疲劳性能和组织特征。NiCrMoV转子窄间隙埋弧焊（NG-SAW）焊接接头组织不均匀，影响焊接接头不同区域的性能。作为评价焊接转子运行性能的重要指标之一，对比研究了母材、焊缝和热影响区的疲劳裂纹扩展行为。结果表明，当应力比R为0.1时，BM的疲劳裂纹扩展门槛值（ΔKth）高于WM和HAZ，但随着R的增大，二者的疲劳裂纹扩展门槛值（Δ Kth）非常接近。通过优化的腐蚀工艺，显示的显微组织，在WM和回火马氏体在HAZ中的粒状贝氏体，导致其近似等效的疲劳裂纹扩展阻力与BM。试验结果表明，大截面NiCrMoV转子焊接接头的疲劳性能满足设计要求，为NG-SAW在大尺寸转子制造中的应用提供了依据。
The fatigue property and microstructure characteristics of the welded joint for nuclear power rotor with heavy section, were systematically reported in this paper. The welded joint microstructure is inhomogeneous for NiCrMoV rotor made by narrow gap submerged arc welding (NG-SAW), which could affect the properties in different zones of welded joint. As one of the important indicator to evaluate the running performance of welded rotor, the fatigue crack propagation behavior of the base metal (BM), weld metal (WM) and heat affected zone (HAZ) was comparatively studied. It was found that the fatigue crack propagation threshold (ΔKth) of BM was higher than that of WM and HAZ as stress ratio (R) was 0.1, but ΔKthwas very close to each other asRincreased. The microstructure, revealed by an optimized corrosive process, was granular bainite in WM and tempered martensite in HAZ, leading to their approximately equivalent resistance of fatigue crack propagation with BM. The experimental results showed that fatigue properties of welded joint for NiCrMoV rotor with heavy section could meet the design requirement, and also push NG-SAW into manufacturing large size rotor.