SURFACE INSPECTION METHOD, SURFACE INSPECTION DEVICE, MANUFACTURING SYSTEM, METHOD OF IDENTIFYING DEFECT FORMED AREA, AND MANUFACTURING METHOD OF STEEL PIPE

摘要

A surface inspection method for a steel pipe detects a surface defect on a hot steel pipe, and includes: an imaging step of imaging a self-luminous image of the hot steel pipe; a correcting step of making more uniform luminance variation in a circumferential direction of the self-luminous image and correcting the self-luminous image; and a detecting step of detecting a surface defect based on the self-luminous image corrected at the correcting step.