Experimental Study on Feeding Efficiency of Exothermic Insulating Covering-Agent for Risers of Large and Medium-Sized Ductile Iron Castings
The performance requirements of covering-agents for large and medium-sized ductile iron riser are briefly described in the paper,and a new characterization and testing methods for riser feeding efficiency is proposed,which is carried out the systematically research and comparison with the new-type of large and medium-sized ductile iron riser exothermic insulating covering agent and congener product from two well-known companies at home and abroad by mean of practical production trials.It can be seen from the test results that:the new-type of exothermic insulating covering agent for the riser of large and medium-sized ductile iron castings achieves a comprehensive balance of ignition temperature,ignition time,heat release speed,heat release value,and production cost for exothermic reaction,with the characteristics of low cost and environmental friendliness.The new covering agent has a low fluorine salt content,and there are no defects such as coarse graphite balls or poor spheroidization at the root of the riser,which has little effect on the morphology of graphite balls on the surface of ductile iron castings.The relative feeding efficiency of new covering-agent is up to 50％for the risers of large and medium-sized ductile iron castings,which is superior to similar products from two well-known companies that have been compared and tested,and can better meet the production requirements of large and medium sized ductile iron castings of high-end equipment.The relative feeding efficiency of the riser which was newly established indicates the comprehensive impact on the total volume and shape of the riser sinking(i.e.the safety height of the riser),and more accurately characterizes the actual feeding capacity and effect of the riser than the traditional feeding efficiency of the riser.
万方数据
维普
