镀锌钢件成型非金属复合材料黑变分析及防护措施

Analysis of Blackening of Galvanized Steel in Forming Non-metallic Composite and Protective Measures

某含镀锌钢件组件产品在成型非金属复合材料时,钢件外露部分发生黑变现象。通过对黑变原因进行理论分析及试验验证,得出在高温和水存在的环境下,镀锌钝化层中的Cr^(6+)和甲醛及水反应,生成Cr^(3+)(H_(2)O)_(6)水合铬离子,使产品表观呈现黑色。采用铝基胶带及亚敏胶带等使产品隔绝外界气体,避免镀锌钢件发生反应,并通过试验验证。为类似镀锌钢件组件在成型非金属复合材料时避免黑变提供了一种理论分析方向及防护保障措施。

In the process of forming non-metallic composite material,the exposed part of a galvanized steel component was blackened.Through theoretical analysis and experimental verification of the cause of blackening,it is concluded that in the environment of high temperature and water,formaldehyde and Cr^(6+)in the zinc passivation layer react with water to produce Cr^(3+)(H_(2)O)_(6) hydrated chromium ion,which makes the product appear black.In this paper,aluminum base adhesive tape and imin adhesive tape are used to insulate the product from the outside gas to avoid the reaction of galvanized steel and it is verified by experiment.This paper provides a theoretical analysis direction and protective measures to avoid blackening of similar galvanized steel components in forming non-metallic composite materials.