10Ni3CrMoV钢CO_2激光多层焊的接头组织与性能

Microstructures and properties of CO_2 laser multi-pass welded joint of 10Ni3CrMoV steel

与传统电弧焊相比,激光焊接厚板优势明显。采用纯激光焊和激光电弧复合焊等多道焊接技术实现了28 mm厚10Ni3CrMoV钢的高效焊接,采用光学显微镜分析焊缝、热影响区和焊缝重叠区的组织,激光复合焊缝组织主要为针状铁素体,纯激光焊缝、粗晶区和细晶区组织主要为板条马氏体,激光复合焊缝重叠区组织为粒状贝氏体+马氏体,纯激光焊缝和激光复合焊缝重叠区组织为马氏体+少量粒状贝氏体。测试了焊接接头的力学性能,结果表明,激光复合焊缝金属的冲击韧性较高,焊接接头的抗拉强度和屈服强度与母材相当,延伸率略小于母材,焊接接头的最大硬度小于360 HV,弯曲性能合格。

Compared with traditional arc welding,laser welding of thick plate has a huge superiority. 10Ni3CrMoV steel with a thickness of 28 mm is efficiently welded by pure laser welding and laser hybrid welding using muhi-pass welding techniques.Microstructure in the weld,heat affected zone and weld overlap zone of 10Ni3CrMoV steel is studied used with OM.The microstructure of the laser hybrid weld primarily consists of acicular ferrite.The microstrueture of the pure laser weld, coarse-grained zone and fine-grained zone mainly includes lath martensite.The microstructure in the overlap zone of two laser hybrid welds is mostly composed of granular bainite and martensite.The mierostructure in the overlap zone of the laser hybrid weld and pure laser weld is mainly composed of martensite and a small amount of granular bainite.The mechanical properties of welded joints are comprehensively tested.The results show that there is a higher impact toughness of laser hybrid weld.The tensile strength and yield strength of the welded joint are nearly equal to that of the base metal,while the elongation of welded joints is slightly less than that of the base metal.The maximum hardness of welded joints is less than 360HV. And the bending performance can meet the requirements.