重量法测定电镀锌板和热镀锌板镀锌质量的比较

根据GB/T1839-2008采用的重量法分别测定了电镀锌板单面镀锌质量和热镀锌板单面镀锌质量;利用辉光放电发射光谱法测定电镀锌板和热镀锌板的镀锌质量,并表征了溶解前后电镀锌板和热镀锌板的镀层结构。结果发现:热镀锌板和电镀锌板镀层结构略有不同,但重量法能有效溶解镀锌板的镀层,使纯镀锌层、锌铁交界层及渗入钢基中的锌全都溶解下来。此外,试验还发现重量法和辉光放电发射光谱法测定电镀锌板和热镀锌板镀锌质量的分析结果有较好的一致性,这也进一步证明重量法是测定不同类型镀锌板的镀锌质量的较准确方法。另外,根据辉光放电发射光谱法测定不同镀锌板镀层结构的分析结果及电感耦合等离子体原子发射光谱法(ICP-AES)测定镀层中铁和铝含量的分析结果,讨论了重量法测定电镀锌板及热镀锌板镀锌质量误差的来源和大小。发现引起重量法测定不同镀锌板的误差主要由镀层中除锌元素以外的铁和铝元素的溶解引起的。而重量法测定电镀锌板镀锌质量的误差要远远小于重量法测定热镀锌板镀锌质量误差,这说明重量法更适合电镀锌板镀锌质量的测定。

Comparative analysis of zinc coating mass on electro-galvanized steel sheet and hot-galvanized steel sheet by gravimetric method

The zinc coating mass of electro-galvanized steel sheet and hot-galvanized steel sheet were measured according to the GB/T 1839-2008, which is gravimetric method. The zinc coating mass of the electro-galvanized steel and hot-galvanized steel was determined by glow discharge optical emission spectroscopy (GDOES). And the coating structure of both galvanized steel sheet before and after dissolution was also characterized by GDOES. It was found that the structures of hot-galvanized steel and electro-galvanized steel were slightly different. And the coating of galvanized steel sheet could be dissolved by gravimetric method, to coating included pure zinc coating,zinc and iron junction layer and zinc permeated in steel matrix totally dissolved. Furthermore, the result showed excellent uniformity which existed between gravimetric method and glow discharge optical emission spectrometry when determining the zinc coating mass of both sheets. This further demonstrated that gravimetric method was relatively accurate for determining zinc coating mass in different types of galvanized steel sheet. Besides, the error source and size of zinc coating mass of both sheet by gravimetric method were discussed according to the results of GDOES and the content of iron and aluminum in zinc coating by inductively coupled plasma atomic emission spectrometry(ICP-AES).Research found that the error of zinc coating mass among different galvanized sheet by gravimetric method was mainly caused by the dissolution of iron and aluminum in the coating in addition to zinc. The error of electro-galvanized steel sheet was far more less than that in hot-dip galvanized steel sheet when both were determined by gravimetric method. This indicated gravimetric method was more suitable for determining zinc coating mass of electro-galvanized steel sheet.