Effect of an Increased Silicon Content on the Aesthetic Quality of Stainless Steel18-8 Fine Art Casting with Ceramic Shell Mold

Abstract

Most small foundries normally use stainless steel 18-8 scraps from lathe machine and stamping shop to cast sculpture with ceramic shell mold. These scraps compose of 18% chromium, 8 % nickel, 0.75% silicon and others. Experience with silicon bronze casting using ceramic shell technique led to the belief that silicon made metal flow and weld better, and less defects. Outgrowing of trial-and-error efforts to improve aesthetic quality of stainless steel fine art castings, in this experimental research, silicon of 0.75% by weight is added to stainless steel scraps to bring up the total silicon content to 1.5%. As an outcome, the increased silicon content not only increases fluidity of stainless steel 18-8 during casting but lowers the driving force for the silicon content in the ceramic shell mold from reaction with the molten metal resulting in reduction in pits, pinholes, porosities, non-fill and cold lap defects. This effect, consequently, increases the aesthetic quality of fine art castings. And thus, decreasing the cost of time and labor required for final welding, grinding and polishing of the sculptures.