This paper, prepared by Giel Notten of NTT Consultancy is covering the subject Heat Tints on Stainless Steels. This part is a describing two cases  and follows the general principals and a theoretical background, which was distributed in February 2009 by UreaKnowHow.com. Although the two cases are not directly related to the urea process, it shows the detrimental effects heat tints can have and therefore also of interest for urea plants. Furthermore for a adequate formation of a passive C2O3 layer on stainless steels in carbamate solutions an optimum starting condition of the material is very important, so without heat tints. Finally the combination of chloride containing cooling water and stainless steel is typically also the case in urea plants. So let us learn some lessons from other processes.

2009 03 Notten NTT Consultancy Heat tints on stainless steels cases.pdf