Evaluation of Cast Iran Blackening Process

Bkack oxide coating is a conversion coating type which applied on different materials such as copper alloys steels and cast irons.special composition of cast irons makes it difficult to applying this type of coating in this research different parameters have been investigated on balckening process.Gray cast iron whith special composition have been esed black oxide coating process in different temperatures and times different chemical compositions of coating bath pre-preparing condition of coating surface have been investigated and their effects on coating quality have beensearched the results had shown thet by increasing the coating temperature and time the coating thickness increase but protecting effect decrease.Also, chemical compostition of coating bath and syurface quality of casting have important effects on coating quality.

Keywords:

chemical conversion coating , blackening , hot alkaline coating , gray cast iron coating