The Formula And Performance's Research Of Resin Sand Anti-veining Coatings For Iron Casting

Production of cast iron parts using triethylamine resin sand of cold box cores or phenolic resin coated sand have the characteristics of low size precision and surface roughness They are widely used in foundry production for many years. However, the casting using this kind of resin sand frequent lumen veining defect during production such as engine cylinder block cylinder head castings. Reducing or eliminating the veining defect is problem to be solved in the production of casting. This study proposed to develop a comprehensive performance good aqueous leaching paint coating by comparing a variety of the measures to prevent iron veins to provide a cost-effective way to reduce or eliminate the veining defect.Firstly, according to the principle of preventing veins by coating the research gets four features of anti-veining coatings which are the high permeability, chilling resistance and adiabaticty. In order to meet the requirement of these features the research choose zircon powder, graphite powder, diatomite powder, mullite powder, red iron oxide as the refractory aggregate.Next, in order to meet the requirements of coating conventional performance, through experiments the addition amounts of all supplementary material are determined as follows(mass fraction %): F-80 suspension concentrate 5, modified starch binder 20, surfactant6.6.Finally, based on the tow ideas of anti-veining which are high permeability adiabatic coating and high permeability adiabatic coating, the refractory aggregate ratio is determined through experiments. The best powder proportion of the high permeability chilling coating(mass fraction %) are: iron powder 75, graphite powder 20, red iron oxide 5. and the best powder proportion of the high permeability adiabatic coating(mass fraction %) are: mullite powder 70, diatomite powder 30, red iron oxide 5.Permeability, high temperature compressive strength and high temperature heat tolerance time of phenolic resin coated sand sample with coating are researched in order to make a standard to assess the effect of coating to prevent veins. The standard has an important referential meaning.Compared with the commercial coating, the anti-veining properties of the high permeability chilling coating is good, close to the standard of the commercial coating, having a high value of practical application.