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进行了X80管线钢埋弧焊接试验,分析了其焊缝的成分、显微组织不均匀性特征。焊缝区的Mn、Ni合金元素的成分不均匀程度较小,Ce、Ti、Al等针状铁素体形核元素在焊缝中心区偏析。熔合区至焊缝中心,焊缝组织变化为:柱状晶形态的先共析铁素体及其分布的粒状贝氏体→大块状的粒状贝氏体→小块状的粒状贝氏体和少量的针状铁素体→针状铁素体。试验分析表明,熔合区附近的焊缝金属难以获得针状铁素体,但可以通过调整合金元素,避免高温铁素体生成,而以粒状贝氏体来提高焊缝区的整体强韧性。
X80 pipeline steel submerged arc welding test was carried out, the composition of the weld, the microstructure heterogeneity characteristics. Weld seam area of Mn, Ni alloy elements of the composition of non-uniform degree of small, Ce, Ti, Al and other acicular ferrite nucleation segregation in the weld center. Fusion zone to the weld center, the weld microstructure changes as follows: the columnar crystalline pro-eutectoid ferrite and its distribution of granular bainite → massive granular bainite → small granular bainite and A small amount of acicular ferrite acicular ferrite. Experimental analysis shows that it is difficult to obtain acicular ferrite in the weld metal near the fusion zone, but the overall strength and toughness of the weld zone can be enhanced with granular bainite by adjusting alloying elements and avoiding the formation of high-temperature ferrite.