Research On Green,High Performance And Low Cost Powder Cast Iron Flow Coating

The foundry industry is the foundation of the machinery industry and one of the important foundations of the national economy.As an important modeling material,foundry coating is applied to the surface of the mold to isolate the molten metal and mold during pouring of the molten metal.Because the casting coating is in direct contact with the molten metal,it mainly prevents the surface of the casting from sticking.Sand,to ensure the surface finish of castings and so on.The quality of the foundry coating directly determines the quality of the casting.Therefore,the casting coating has gradually attracted people's attention.At present,the widely used casting coatings are mainly slurry or paste coatings.The slurry or paste coatings need only add a small amount of carrier liquid or can be used for application before use,which has the advantages of convenient use,but And paste-like coatings contain a large amount of carrier liquid,especially alcohol-based coatings,which have the problems of high transportation cost,unsafe transportation and storage,and refractory bones in the process of transportation and storage of slurry or paste alcohol-based coatings.The material and the carrier liquid are separated,and the phenomenon of "dead precipitation" is likely to occur for a long time,which leads to the scrapping of the coating.Powder coatings,because they do not contain or contain less carrier liquid,greatly reduce transportation costs,and are safe to transport and store.They are used now and are not used due to long-term placement.Therefore,powder coatings are favored by foundries.However,since the powder coating needs to be ready-to-use,it is required that the powder coating needs good performance after simple stirring after adding the carrier liquid,so the powder coating material is required to be much higher than the slurry or paste coating,especially the alcohol.Base powder coatings have not been widely used due to difficulty in lifting.Therefore,there is a need for a low-cost,high-performance alcohol-based powder coating to break through the bottleneck of current powder coating development,thereby promoting the use of alcohol-based powder coatings.The flow coating coating has the advantages of high application efficiency because of its high efficiency application on the surface of the mold,and the flow coating process has been widely used in China.In this paper,the suspending agent composition and preparation process of the foundry coating,the composition of the refractory aggregate,the content of the binder and the preparation process of the powder coating were studied to obtain a high-performance low-cost alcohol-based powder suitable for cast iron parts.Flow coating.The specific conclusions are as follows:(1)Invented a new type of powdery cast iron flow coating paint,which has the advantages of safe transportation,low cost,good leveling,high suspension,and good anti-sand adhesion.Its suspending agent formula is SN suspending agent:lithium-based bentonite=3:7,and the pretreatment process is SN suspending agent:a material=1:1,lithium-based bentonite:a material=1:2.(2)The final determination of refractory aggregates in powder coating formulations:10-20%of flake graphite,30-40%of earthy graphite,35%of quartz powder,3?5%of iron red;the proportion of suspending agent in refractory aggregate:SN suspension agent 1.5%;lithium-based bentonite 3.5%;the proportion of binder to refractory aggregate:resin 1.5%,rosin 0.5%,PVB 0.4%.(3)In the preparation of powder coatings,the suspension agent and other powders need to be prepared separately.When diluting,add the suspending agent to the carrier liquid and stir well,then add the rest of the powder,and apply it on-site after stirring well.(4)Under the best powder coating formula,combined with the best powder coating preparation and dilution process,the best performance of the powder coating is finally obtained as follows:density 1.10g/ml,2h suspension 100%,24h suspension 93%,dripability 0.93g,leveling 130mm,strength 53.2g,viscosity 6.3s,anti-foaming level 8(5)The powder coating is applied to the field casting of medium-sized castings.The self-made powder coating has good anti-sand-stick performance,and has the characteristics of easy sintering and peeling to achieve the effect of commercial coatings.