高强度低合金钢埋弧焊缝成分和显微组织分布特征
Microstructure and Chemical Composition of Submerged Arc Weld Metal for High Strength Low Alloy Steel
杨晓荣， 姚成云， 马德胜
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作者单位：（新钢机械制造有限责任公司，江西 新余 338001）
中文关键字： 高强度低合金钢； 埋弧焊缝； 合金成分； 显微组织； 不均匀性
英文关键字： high strength low alloy steel; submerged arc weld metal; alloy composition; microstructure; heterogeneity
中文摘要：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。
英文摘要： Taking the submerged arc weld metal of X80 pipeline steel as example, the heterogeneity of chemical composition and microstructure of high strength low alloy steel weld were analyzed. The results show that the segregation of Mn, Ni elements in the weld is faintish, but the segregation of Ce, Ti, Al elements which can promote the forming acicular ferrite nucleation is serious in the center of the weld. The microstructure evolving from fusion zone to center of the weld is columnar pro-eutectoid ferrite and granular bainite → bulk bainite → refined banite → minor acicular ferrite → acicular ferrite. Therefore, it is difficult to obtain acicular ferrite for fusion zone, but the whole tenacious properties of high strength low alloy steel weld increase by promoting the formation of granular bainite and restricting the formation of pro-eutectoid ferrite.