Al-Zn-Si coatings on iron-base alloys obtained by batch hot-dip method

The aluminium addition in the zinc bath causes an increase in corrosion resistance of the obtained coatings. The work presents investigations results of obtained coatings by batch hot dip method in the alloy bath containing Zn + 55%Al + 1.6%Si. The surface treatment process of iron alloys before metallization is presented. Kinetics of the coating growth in the tested alloys was determined in the changeable conditions of bath temperature and dip time. The structure of coatings and their phase composition was revealed. As the result of the performed tests it has been found that an increase in total thickness of coatings in the dip time function at stable temperature has character close to parabolic, whereas an increase in the transient layer has character close to linear. (author)