磷化处理铸件发白原因研究

介绍了磷化处理工艺原理和工艺流程,对缸盖铸件磷化处理后颜色变白的原因进行了试验研究。最后得出如下结论:(1)磷化处理工艺所使用的各种处理溶液均能与磷化液反应并生产白色沉淀;而且磷化处理本身的副反应也会产生磷化沉渣。(2)为避免磷化各工序处理液互相污染,要在各工序前后增加适当的辅助措施,如在每个工序之后增加吹风、在磷化前后多增加几道水洗工序等。此措施对于结构复杂的工件更为必要。(3)为避免磷化液产生沉渣,不但要选取适合的磷化液和处理温度,而且要增加过滤装置,对磷化液进行过滤,保证磷化液纯净以及处理件的处理效果。

An Investigation on the Reason Causing Phosphating Treated Casting to Show White Color

The principle and process flow of the phosphating treating process were introduced. Test and investigation was conducted on the reason causing the surface col, or of eyhnder head casting to be changed into white after having been phosphating treated. It was concluded finally： （1）all treating-used solutions could react with the phosphating solution and produce white sediment and the subsidiary reaction of the phosphating treatment could also produce phosphating sediment; （2）in order to avoid various procedures of the phosphating process to be poUuted by each other,it＇s necessary to add relevant assistant measures such as adding blowing after every procedure,adding several water-washing procedures,etc. This measure would be even more necessary for the complicated workpieee; （3）in order to avoid the phosphtating solution to produce sediments,it＇s necessary not only to adopt appropriate phosphating solution and appropriate treating temperature,and also to add filtering unit to filter the phosphating solution to ensure the purity of the phosphating solution and the treating effect of the treated workpiece.