激光焊接热输入对26Cr-3.5Mo铁素体不锈钢组织性能的影响

发布时间：2019-04-22 08:58

【摘要】：采用连续激光焊接工艺对26Cr-3.5Mo铁素体不锈钢进行焊接,研究了激光焊接热输入(HI)对焊接接头显微组织和力学性能的影响。采用光学显微镜(OM)、扫描电子显微镜(SEM)、透射电镜(TEM)和能谱分析仪(EDS)研究焊缝显微组织和析出相的析出规律,采用维氏显微硬度仪和拉伸试验机对焊接接头的机械性能进行测试。结果表明,焊缝中心产生细小的等轴晶,随着激光焊接热输入的增加,焊缝中心等轴晶区的宽度增加,其占整个焊缝截面的比例先增加再减小。热影响区(HAZ)宽度较窄,为0.1~0.2 mm,且没有发生明显的晶粒粗化现象。焊接接头HAZ发生软化,其显微硬度值低于焊缝和母材。焊接接头抗拉强度与母材相当,但断后伸长率小于母材,且随激光焊接热输入的增加而减小。
[Abstract]:26Cr-3.5Mo ferrite stainless steel was welded by continuous laser welding process. The effect of laser welding heat input (HI) on microstructure and mechanical properties of welded joints was studied. Optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy spectrum analyzer (EDS) were used to study the microstructure and precipitation law of the weld. The mechanical properties of welded joints were tested by Vickers hardness tester and tensile tester. The results show that there are fine equiaxed crystals in the weld center, and the width of the equiaxed crystal zone in the weld center increases with the increase of laser welding heat input, and the ratio of the equiaxed crystal zone to the whole weld cross-section increases first and then decreases. The width of (HAZ) in the HAZ is narrower, 0.1 脳 0.2 mm, and there is no obvious grain coarsening phenomenon. Welding joint HAZ softens, its micro-hardness value is lower than weld and base metal. The tensile strength of the welded joint is similar to that of the base metal, but the elongation after break is lower than that of the base metal and decreases with the increase of laser welding heat input.
【作者单位】：天津大学材料科学与工程学院;天津大学天津市现代连接技术重点实验室;宝山钢铁股份有限公司研究院;
【分类号】：TG456.7;TG142.71

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