镀锌球铰在通过某减震器厂的涂装线硅烷前处理工序后,镀层出现发黑。其原因是镀锌层在硅烷处理过程中受到了腐蚀。镀锌钝化后增加合适的封闭工艺能有效解决该问题。 The zinc coating on ball joint was blackened after silane pretreatment in the painting line of a shock absorber manufacturer due to the corrosion of zinc coating during the silane pretreatment process. Sealing properly after passivation of zinc coating is available to solve such problem.