Novel inspection of welded joint microstructure using magneto-optical imaging technology

摘要

A novel method for measuring differences of microstructure by advanced use of the Faraday magneto-optical effect is proposed.Two groups of YAG laser welds on Q235 have been investigated in order to compare MO imaging and traditional methods.Microstructure images have been compared with MO images,and MO diagrams display different colors and gray scales for the base metal,the weld zone,and the heat affected zone.Experimental results indicate that the welded joint microstructure can be inspected by MO imaging without metallographic preparation.