扫描路径对DP780双相钢激光点焊成形特征及组织性能的影响

    Effect of Scanning Path on Laser Spot Welding Forming Characteristics and Microstructure, Properties of DP780 Dual-phase Steel

    • 摘要: 为了探究激光焊接DP780双相钢的工艺特性,开展了不同扫描路径下激光点焊DP780双相钢的实验,对比不同摆动路径对焊缝成形、组织及剪切性能的影响。结果表明:不同扫描路径下激光点焊的焊缝组织相似:焊缝区组织为板条马氏体、贝氏体以及少量铁素体,热影响区组织为尺寸不均匀的块状铁素体、贝氏体以及少量马氏体。施加不同形式的扫描方式,使焊缝内铁素体和贝氏体在一定程度上有所增加,马氏体尺寸减小。扫描激光焊接头焊缝区的平均硬度有所降低,但软化区内最小硬度明显升高;扫描激光焊在一定程度上增大焊缝熔宽,降低焊缝熔深,可抑止气孔的形成;扫描激光焊接头的断口形貌主要由光滑界面和韧窝组成。

       

      Abstract: In order to explore the process characteristics of laser welding DP780 duplex steel, the laser spot welding experiment of DP780 duplex steel under different scanning paths was carried out to compare the influence of different scanning path on the weld formation, microstructure and tensile shear property. The results show that the weld microstructure of laser spot welding in different scanning paths is similar:the weld area is lath martenite, bainite and a small amount of ferrite; the heat affected zone is uneven massive ferrite, ferrite and a small amount of martenite. However, after application of different scanning methods, the ferrite and bainite in the weld increases in some extent, and the size of martensite is reduced. The average hardness of the weld area of the scanning laser welding joint is reduced, and the minimum hardness of the softening area increases. Laser scanning welding increases the width of the weld, decreases the weld penetration, and can inhibit the formation of pores. The fracture of the scanning laser welding joints is mainly composed of smooth interface and dimples.

       

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