Study on black spot defect of chromium-free fingerprint-resistant hot-dip aluminized zinc steel plate
ZEISS Merlin Compact field emission scanning electron microscope,OXFORD X-max N energy spectrometer,laser confocal microscope and other analytical techniques were used to analyze the causes of black spot defect of chromium-free fingerprint-resistant hot-dip aluminized zinc steel plate.And the improvement measures were also put forward.The results show that the black spot defect is mainly due to the uneven distribution of the passive film caused by the uneven thickness of the coat-ing.The passive film is thick where the coating is thin,and the passive film is thin where the coating is thick.During the transportation of the steel coil,the friction between the steel plate layers causes the passive film to be damaged or even detached,resulting in different reflectivity of the steel plate surface,resulting in black spot defects.
hot-dip aluminized zincblack spotmicro-morphologypassive film
万方数据
维普
