Effects of Si and RE on the hot-dip aluminizing HK40heat-resistant steel were investigated.By means of optical microscope
scanning electron microscope and energy spectrum analysis
the microstructure and element distribution of coating were analyzed.The phase constitute of coating was investigated by X-ray diffraction
and the hardness testing was carried out at different zone from steel base to coating.The results show that the surface thickness of coating is decreased and exhibits more smoothly
meanwhile
the coating and the matrix are characterized by metallurgical bonding with the addition of Si and RE.More FeAl3and Fe2Al5phases appear in coating
and the micro-hardness of transient layer is improved largely.