低碳贝氏体钢双面埋弧焊接头的组织和低温韧性
发布时间：2018-08-20 10:31
【摘要】：对低碳贝氏体钢进行双面埋弧焊焊接,并用光学显微镜和PSW750型示波冲击试验机对焊接接头进行表征,研究了钢的显微组织和低温韧性。结果表明:低碳贝氏体钢双面埋弧焊后,焊缝区的组织为针状铁素体和粒状贝氏体;HAZ的组织为贝氏体铁素体和粒状贝氏体;HAZ熔合线附近的硬度最高,远离熔合线硬度降低并逐渐接近母材金属的硬度;随着温度的降低焊接过程中的凝固偏析、高度集中的位错源来不及松弛应力集中以及分布在晶界上的Ti、Mo等微合金元素形成的碳氮化物,导致焊接接头焊缝区和HAZ韧性降低并在-20℃和-60℃发生韧脆转变。
[Abstract]:The low carbon bainitic steel was welded by submerged arc welding on both sides. The microstructure and low temperature toughness of the steel were studied by means of optical microscope and PSW750 oscillographic impact testing machine. The results show that the microstructure of the weld zone is acicular ferrite and granular bainite HAZ, and the hardness near the fusion line of bainite ferrite and granular bainite is the highest after double-sided submerged arc welding of low carbon bainite steel. The hardness decreases away from the fusion line and gradually approaches the hardness of the base metal; as the temperature decreases, the solidification segregation occurs during the welding process. The highly concentrated dislocation causes too late relaxation of stress concentration and the formation of carbides formed by microalloyed elements such as Tipo Mo on grain boundaries, which results in the decrease of weld zone and HAZ toughness of welded joints and ductile brittle transition at -20 鈩，
本文编号：2193281
[Abstract]:The low carbon bainitic steel was welded by submerged arc welding on both sides. The microstructure and low temperature toughness of the steel were studied by means of optical microscope and PSW750 oscillographic impact testing machine. The results show that the microstructure of the weld zone is acicular ferrite and granular bainite HAZ, and the hardness near the fusion line of bainite ferrite and granular bainite is the highest after double-sided submerged arc welding of low carbon bainite steel. The hardness decreases away from the fusion line and gradually approaches the hardness of the base metal; as the temperature decreases, the solidification segregation occurs during the welding process. The highly concentrated dislocation causes too late relaxation of stress concentration and the formation of carbides formed by microalloyed elements such as Tipo Mo on grain boundaries, which results in the decrease of weld zone and HAZ toughness of welded joints and ductile brittle transition at -20 鈩，
本文编号：2193281
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