短语词组短语welding -seam cleaner 焊缝清理机;焊缝清算机butt welding seam 对接焊缝longitudinal welding seam 纵向焊缝welding seam tracking 焊缝跟踪welding seam image 焊缝图像welding seam traking 焊缝视觉跟踪main welding seam 主焊缝welding seam size 焊缝胶 返回 welding seam