Pack Cementation Coating For 304 & 316L Stainless Steel Alloys By Using Silicon Zing Process

Abstract

In this study, we investigated the synthesis of pack cemented coating on two metallicmaterials (304 & 316L) in order to form silicon compounds on their surface at lowertemperatures (800,900 &950˚C) to avoid sintering of the pack and adhesion of material tothe samples surface.In our investigation silicon was used as a master alloy and alumina (Al2O3) as a fillermaterial. Also ammonium chloride was used as an activator with different weightpercentage (5,7 &10%) ,in order to increase the efficiency of the coating layer formationprocess. Silicon zing of two alloys which are 304 & 316L by pack cementation processaccording to light optical microscope examination (LOM), the coating layer formation is atemperature and activator weight percentage dependent process, which means that it is adiffusion controlled reaction. Thus the thickness of sample silicon zed with packcontent 10% activator at 950˚C is higher than the sample silicon zed with pack content 7%and 5% activator and these samples have higher thickness than samples coated at 900˚Cand 800˚C at same conditions. The average coating thickness obtained by silicon zingprocess at 4hr by using different activator weight percentage for two selective alloys are:1- 8.520 – 129.390 am for 304 st.st alloy.2- 75.929 – 192.592 μm for 316L st.st alloy.