1993 Volume 79 Issue 5 Pages 590-596
The hot dip galvanizing mechanism of Si added hot rolled Al killed steel sheets with various surface conditions were investigated. It was found that various factors of steel surface conditions affected the galvanizing reaction. The Zn coating appearance and galvanizing reaction of Si added hot rolled steel sheets were improved by mechanical grinding after pickling. According to the results of AES and ESCA analysis, it seemed that the residual subscale layer (inner oxide layer) of Si added hot rolled steel sheet after pickling was removed by grinding. Therefore Zn coating appearance was improved. Furthermore increase of residual strain and stress on the Si added steel surface by grinding were also observed by X-ray diffraction method. It seemed that active sites such as the lattice deffects of substrate increased by mechanical grinding, and therefore Zn-Fe reaction increased.
