Researches On Instant Inoculation Facility And Inoculation Process Of Ductile Iron

Hole defects such as heavy section ductile iron castings production,existence nodalizing grade low,unstable mechanical properties,surface slag inclusion,shrinkage voids impact product quality seriously. In order to improve the quality of casting products,this thesis studies heavy section slippery pillow of boring machine ductile iron, adopts combination of production test and microscopic analysis method.It researches company ductile iron electric furnace smelting wiht technology and production, inoculation, instant inoculation facility and instantaneous inoculation of heavy section ductile iron castings influence on the performance of the organization systematically, the result of which will improve the quality of casting products greatly.With metallographic organization the design requirements achieve stability of mechanical properties、improving graphite morphology and controling shrinkage hole, shrinkage defects as a starting point, this author analyze the heavy section nodular iron casting furnace smelting production technology of key technologies based on the recommended, which can be used for the production of slippery pillow of boring machine ductile iron with chemical composition, parameters and main points.Based on the analysis of common inoculation method and instant inoculation facility, combined with the actual production company of heavy section ductile iron castings,This author design and production of the instant inoculation facility of heavy section ductile iron castings. It use very simple, by replacing the material limiting mouth to control the stream inoculant flow.When pouring, the operator pull the upper end of the wire rope, When pouring, the operator pull the upper end of the wire rope, to make the plug from away outlet, stream inoculator will enter the iron flow which in the runner cup to achieve stream inoculation.Pouring is completed,the operator pull the down end of the wire rope,to make the plug block outlet and stop remaining inoculator in the facility outflow.The author design instant inoculation facility of heavy section ductile iron castings can meet the practical needs of production.This thesis design lots of test schemes,such as eliminates stream instantaneous inoculation, make YFY-1A, SPI, SiRE stream instantaneous inoculation,to study the novelizer, inoculant types, dosage, adding method, pouring temperature and micro alloying influence factor of heavy section ductile iron castings and mechanical properties.The results show that the increase of steel scrap rate, significantly improve the nodulizing grade; by increasing Si inoculation outside the furnace, enhanced the inoculation effect and refined graphite; SiRE inoculant containing AL for stream inoculation, increased the number of nodular graphite; add to the Y and micro alloying elements, improving the nodulizing grade、increasing the solidification late fine dispersed graphite quantity and reduce the shrinkage porosity tend to have more help.