how to clean cast iron Inoclulating iron through filters.
In this story:Mold breeding and ceramic foam filtration are practical methods to obtain high efficiency cast iron.* Recent investigations by inserting inoculation particles in the filtration center combine these two methods at one point in the mold.* This article introduces in detail the effect of pregnancy care agentsThe filter assembly works with molten iron in different mold and heat conditions.Since the first introduction of the metal casting industry in 1960 s, in-Mold breeding helps to produce castings with stable tissue.Over the years, by placing a pregnancy care agent, such as a sintering block, a cast block, a particle, or a block of size, in a mold, this technique has been used and has become a common practiceIn order to be effective, the incubation agent must inhibit the formation of carbide and D & E-type graphite.But to make good castingsin and day-The black metal casting facility should strive to cast parts that not only have the correct microstructure, but also have clean metal.Like in-Mold inoculation, ceramic foam filtration is no stranger to the industry and has been recognized for effective removal of impurities and modification of fluid flow.In order to obtain sufficient cast iron applications, the filter must provide high heat resistance, excellent corrosion resistance and good dimensional stability at low cost.Recent developments have focused on combining these two technologies with proven benefits ---Place the pregnancy agent inside the filter, and then place the pregnancy agent inside the gate system.Using an in-The filter vaccination system provides several technical and economic advantages.It actually eliminates the chill generated by the fading of the pregnancy agent, improves the mechanical properties and operability of the iron, while providing effective filtration.Also, in-Mold inoculation will increase the consistency of each mold incubation process, which will reduce the organizational differences between castings.The in-When the automotive metal casting equipment appears cold and hard points on the components, the filter inoculation system is further studied.The company's current flow vaccination device lacks the required reliability, so the facility studies the choice of secondary or safety vaccination agents.Other metal casting companies have encountered similar situations.Through preliminary experiments, it was found that the pregnancy agent filter can be used as a primary pregnancy agent to completely replace the need for flow vaccination.Further investigations were therefore conducted to identify the effectiveness of the joint applicationMold inoculation particles with thin filterCast application of wall gray iron.The study consists of two phases: Evaluation of dissolution behavior of pregnant agent particles embedded in ceramic foam filters;And evaluate the effectiveness of pregnancy care agentsThe filter assembly takes the shape and cleaning of the molten metal.This paper discusses the methods of investigating pregnancy care agentsFiltering behavior and what is found from each study.Completely disappeared in the first part of the investigation, eight 0.03-lb.(15-G) produce and check the pregnant agent particles to see how well they dissolve when immersed in molten iron.Each 1-in.The diameter particles are made of ferrosilicon and include 5.5-6.5% zirconium (zirconium) indicates dissolution.The particles are embedded in the central cavity of a 2.36-in (60-Ceramic filter with diameter (mm) (Fig.1).This inoculant-The filter assembly is placed in the nobake pouring cup and pig mold assembly (Fig.2), with iron from 2,327-2,570F (1,275-1,4100.At different pour temperature and pour time length, the change of each pregnancy agent was tested 3 to 5 times.[FIGURES 1-2 omitted] then weigh the pig casting to determine the amount of iron passing through the incubation agentFilter component.Two of the pig castings were drilled at the top of 5 points, of which 0 points.04 lbs.Collect (20g) turns at each point and analyze the zirconium content.It was found that the content of zirconium in Iron increased 10 times after inoculation, 64-70% of the zirconium available in the pregnant agent particles was recovered in both castings (Table 1 ).Generally, all particles in the pregnant agent granules are dissolved at a similar rate.Next, a visual examination of any undissolved pregnancy agent material reveals the difference in pellet behavior.The first group of four pregnant agent particles dissolved in most cases, and the second group of pregnant agent particles dissolved in all cases, even at the lowest temperature (2, 328F/1, 275C) the minimum amount of iron is poured (34 lbs )./15.4 kg).In addition, the analysisMetal inclusion in the filter.No filter was found to contain any residual ferrosilicon material.There are only small particles of gray iron and refractory in the samples where the pregnancy agent is not completely dissolved.Although the first survey proved that the particles were fully dissolved, more studies must be carried out in order to better evaluate the pregnancy agentFilter properties.As a result, two completely dissolved pregnant agent particles were selected for another survey.Fluid-Flow analysis of five continuous wedge cavities nobake test dies (Fig.3) to further study how the flow properties of metals affect pregnancy care agents-Filter component.In addition, one end of each cavity is designed to completely stop the iron flow immediately after filling.Insert the pregnant agent particles into a 2.16 x 2.16 x 0.86-in.(55 x 55 x 22-(Figure mm) filter4), put it in the mold.[FIGURES 3-4 slightly] Iron is poured at a flow rate of 1-13 lbs./in./Second, for the first group of eight castings at temperatures of 2, 46 f (1, 350C), 2, 55f (1, 400C) and 2, 64f (1, FOMC, the temperatures of the eight castings in the second group were 2, RWF (1, 329C) and 2, 680f (1, 471C ).After cooling, remove three wedges of each casting from the hole and drill holes in three positions at the end opposite the cross section.Chemical analysis of residual zirconium content was carried out on these holes.An analytical model was established that the temperature and flow rate were expected to affect the dissolution behavior.However, the differences between the analytical model and the experimental data show only partial correlations (Fig.5-6).[FIGURES 5-6 omitted] Nevertheless, the general properties of particle dissolution are positively correlated with the speed of the iron liquid flow, and it is proved that the rate of zirconium dissolution and recovery can be predicted.Keep it clean thoughThe filter assembly shows that the pregnancy agent will dissolve correctly and still needs to prove that the Assembly provides clean and goodInoculation metal for casting.The second part of the survey consists of several criteria focusing on cooling trends of iron, microstructure (graphite form and metal structure), cleanliness and integrity of the filter.Two separate pregnancy agents of ferrosilicon were used at this stage: one rich in zirconium and the other rich in Sr.The inoculant-The filter component is the same as the filter component used in the flow analysis.Another nobake mold was used, but this mold design has two identical casting cavities in parallel.Each casting cavity contains test plates and cold wedges with separate filter prints.The inoculant-The filter assembly is placed in the filter print of one test board, and the same filter without the pregnant agent particles is installed in the same position of the other board (Fig.7).Each test cavity contains a cold wedge for casting the iron for the mold to be poured at 2,700 f (1, 482C.[Figure 7 omitted] by measuring the depth of each cooling, the cooling trend of iron after cooling of the casting was studied.Found the zirconium-The freezing reduction with particles is the most consistent (Table 2-3).Then, the microstructure of the polished sample is checked for each cooling wedge.In all cases, the inoculation of iron significantly reduced the formation of carbide at a depth of 0.2 in.(5mm), increase the formation of A-type graphite (this enhances the mechanical properties and the machining properties of gray iron castings) and reduce the percentage of type D and Type E graphite (this can indicate that iron is poorly vaccinated in specific areas of the casting ).The pregnancy agent also helps to form a pearl matrix.This confirms that the tile pregnancy care agent filter assembly can effectively reduce the formation of iron carbide (which can accelerate tool wear and reduce the operability of castings) while promoting the formation of A-type graphite in the Pearl rock matrix.After this process, the focus is shifted to the test casting inside the mold.In order to determine the cleanliness of the casting, the mating surface of the test plate was processed to reveal any secondary surface defects and inclusions.Remove each inclusion from the Test Board and check it.The two plates were then studied to determine the properties and morphology of the package.In all cases, the area that appears to be an underground inclusion after processing is actually a void or air hole in the casting.All defects examined do not contain any foreign material, indicating that the filter prevents any particles or foreign inclusions in molten iron from entering the casting plate.Next, each of the test castings produced were inspected, but it was found that most of them did not contain the pregnancy agent material.The materials observed in several samples were evaluated and they were found to be re-oxidation products commonly associated with gray iron filtration, but none of the samples contained any residual silicon in the filtration areaFiltering out these surveys shows how-Mold inoculation can benefit cast iron.The pregnant agent particles are properly dissolved and helped to go with the filter unlessMetal material from metal.Although further investigation should be conducted to prove the results of the investigation here, in-Mold inoculation and recent filtration are two procedures that have benefited from metal casting facilities over the years.By combining the two into a method, it helps eliminate a step in the casting process without sacrificing quality.This can reduce production costs while speeding up the production cycle and help metal casting facilities achieve their ultimate goals.This article is adapted from a paper (04-092) proposed at 2004 Metal Casting Conference.For more information on "improving the breeding of iron globes", seeLekakh and C.R.Loper Jr., 2003 AFS transactions, Document No.03-103.K. "filter the basics: Who, What, Where, Why and how to filter ".Adams, E.J.Williams, S.Annan, modern casting, March 200219-21.Yury S.Lerner is the main Professor of the university's foundry Education Foundation.Cedar Falls in northern Iowa.Don Craig is product manager and Leonard Aubrie is vice president of new product development at Selee Corp.Henderson, New YorkC.Thomas Lucia is the leader of a research group, and Roland Siclari is the manager of technical services and product development for Pechiney Electric Metallurgical in Paris.