During the iron casting process, there are different requirements for every working procedure. The first step of the iron casting process is to smelt the molten iron which need to meet corresponding demand of smelting as the iron has different grades and mechanical performance requirements. Then add the nodulizing agent which is usually with rare earth ferrosilicon magnesium alloys in our country if you want to cast the ductile iron. The quantity of nodulizing agent in the iron casting process is according to the composition of the molten iron, amount of iron water and production experience. The next step is to add inoculantagent which typically is 75 ferrosilicon and the amount is similar to nodulizing agent. Then pouring castings after stirring the molten iron well. In normal circumstances, the spheroidizing molten iron must be casted within 15 minutes. Otherwise it will cause spheroidizing recession during the iron casting process. But the nodulizing agent with calcium, barium and strontium can delay the recession to a certain extent. There are lots of methods to add thenodulizing agent and inoculant agent. Some manufacturers join them in furnace, some in a chute, some at the bottom of the bag and so on.