采用自主研发的分离式激光整形和环形反射聚焦系统,对小口径管件内壁进行了重熔,并对重熔后的试样进行了宏观成形与显微组织分析。结果表明:该系统无需旋转机构即可实现对口径在30 mm以下的管件进行内壁重熔;在优化的工艺参数条件下,重熔层成形质量良好,无螺旋形搭接边和焊接鱼鳞纹;熔池呈圆环形,可有效防止热裂纹的产生;随着激光扫描次数增加,重熔层的熔深先增大后变小;随着扫描速率增大,重熔层的熔深降低,表面粗糙度降低。

A self-developed laser processing system consisting of discrete designed transformation module and reflected ring focusing module is employed to re-melt the inner face of small-bore tube, and the macro appearances and microstructures of remelted layers are analyzed in details. The results show that the processing system can re-melt the inner face of the small-bore tube with diameter below 30 mm without a rotating mechanism. The quality of remelted layer is good without spiral overlapping edges and ripples under the optimum processing parameters. The molten pool is ring-shape and the cracking tendency is remedied obviously. The penetration of remelted layer increases first and then decreases with the increase of the number of laser scanning, and the penetration and surface toughness reduce with the increase of scanning speed.