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成功研制了符合三代核电机组使用要求的国产碳钢焊条CHE507HR2。通过控制渣系、熔敷金属化学成分和夹杂物类型获得了高纯净度的熔敷金属及以针状铁素体为主的焊缝组织,在高温1 h、16 h、40 h不同热处理保温时间下,焊条的力学性能均满足同一技术条件要求,熔敷金属抗拉强度与屈服强度同步减小,但屈强比变化不明显,冲击韧性显著提升,其余指标变化不显著。随着热处理保温时间的延长,熔敷金属显微组织碳化物弥散析出并粗化,使抗拉强度降低、冲击韧性提高。
Successfully developed in line with the requirements of third-generation nuclear power units made of domestic steel electrodes CHE507HR2. High purity weld metal and acicular ferrite-based weld microstructure were obtained by controlling the slag system, the chemical composition of deposited metal and the types of inclusions. The microstructures of the welded joints were characterized by different heat treatments at 1 h, 16 h and 40 h Time, the mechanical properties of the electrode meet the requirements of the same technical conditions, the tensile strength of the deposited metal and yield strength decreases simultaneously, but not obvious changes in yield ratio, impact toughness increased significantly, the other indicators did not change significantly. With the extension of heat treatment holding time, the deposited metal microstructure carbides dispersed precipitation and coarsening, so that the tensile strength decreases, impact toughness increased.