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采用窄间隙埋弧焊工艺在相同焊接参数下对2.25Cr-1Mo-0.25V钢进行焊接,选择冲击功相差较大的两个焊缝进行化学成分分析、力学性能测试、宏观断口及显微组织观察,并分析了焊缝冲击功不稳定的原因。结果表明:焊缝冲击功出现波动是由化学成分和组织不同造成的;焊缝中的锰、硅元素含量较多时,冲击功低,韧性差;组织粗大,板条贝氏体较多时,韧性和塑性低;组织细小,粒状贝氏体较多时,韧性和塑性较高;当冲击试样缺口开在板条贝氏体较多的区域时,M/A岛趋于直线排列,容易形成裂纹,冲击功较低。
The narrow gap submerged arc welding process was used to weld 2.25Cr-1Mo-0.25V steel under the same welding parameters. The chemical composition analysis, mechanical property test, macroscopic fracture and microstructure Observation and analysis of the weld impact energy instability reasons. The results show that the fluctuation of weld impact energy is caused by the difference of chemical composition and microstructure. When the content of manganese and silicon in the weld is large, the impact energy is low and the toughness is poor. When the structure is coarse and the bainite is large, the toughness And plasticity is low. When the microstructure is fine and the granular bainite is more, the toughness and plasticity are higher. When the notch of the impact specimen is opened in the bainite area of the slab, the M / A islands tend to align in a straight line and the cracks easily form Impact energy is low.