Ferro Silicon Magnesium for Foundry and Casting Iron Nodulizer is a magnesium nodularizing inoculant. It reduces chill during solidification and improves machinability of ductile iron.
It contains magnesium and rare earth elements to promote spheroidization in the iron, besides minimizing chilling tendency. It also has strong deoxidation and desulfurization effect on molten iron.
The production of ductile iron requires nodulizing with a magnesium ferrosilicon master alloy. Many systems have been developed to carry out the nodulizing treatment in a ladle. However, the handling of these alloys is difficult and time consuming due to their slow dissolution in the molten iron. Furthermore, the alloy granules are often swept into the casting resulting in defects.
The present invention provides a magnesium ferrosilicon nodulizer with strong spheroidizing ability which can be used in a cast iron melt treatment. The magnesium ferrosilicon nodulizer comprises 5-15% magnesium, 60-80% silicon, 0.1-1.5% calcium, 0-2.5% rare earth and the balance iron. The nodulizer is effective in promoting graphite nodules in the ductile iron melt. The presence of the nodulizer in the iron melt also prevents formation of oxides, nitrides and sulfides by reducing metal-metal reactions in the melt. Moreover, the nodulizer increases the nodule count in low sulfur base irons. The nodule count is significantly higher in inoculated samples than in uninoculated ones.
Magnesium ferrosilicon alloys can be used as a nodulizer in liquid cast iron to encourage the growth of graphite in a spheroidal or compact form. These nodularizers are available in a wide range of sizes and chemistries to suit all types of treatment processes, including pour-over, sandwich, tundish, flow-through and in-mold.
These nodularizers are stable and react slowly with molten iron, thus reducing the violence of the reaction and avoiding smoke and flare. They can also reduce the number of carbonitrides, oxysulfides and carbides generated during melt treatment, as well as inhibit the formation of nitride nodules.
Unlike other nodulizers, our products do not contain impurities like arsenic, zinc and lead. These interference elements can damage the spheroidizing effect. They can also improve the purity level of casting water and generate low melting compound. In addition, they can remove the impurities from the molten metal thereby improving the quality of the casting. The present invention relates to a magnesium ferrosilicon alloy particularly suitable for in-mold nodulization of ductile iron, comprising from about 5 to 15 percent magnesium, 60 to 80 percent silicon, 0.1 to 1.5 percent calcium and up to 2.5 percent aluminum, with the balance being iron.
The magnesium content of the nodulizer mainly determines its ability to be fully absorbed by the low sulfur molten iron. It is suitable for frequency furnace smelting and can be used as the nodulizing pre-alloy in Plunging, Open Ladle, Overpour/ Sandwich, Trigger and Tundish Cover treatment methods.
The spheroidal graphite iron produced by this magnesium ferrosilicon alloy has a low sulfur level, which reduces the possibility of carbide formation in the cast iron. This makes it particularly valuable for applications in which the spheroidal graphite iron is to be used as a component of the casting.
Commercial SG, which is made by two-stage melt treatment (Mg-treatment followed by inoculation), contains significant amounts of preexisting impurities, including solid films of oxides and other inclusions such as nitrides and sulfides. Secondary ion mass spectroscopy indicates that these inclusions can play a role in the nucleation of SG. However, in high-Ti irons they may cause nitride nucleation rather than oxide-sulfide nucleation.
The low melting compound of Ferro Silicon Magnesium makes it possible for it to be added into molten iron easily, without the risk of forming an insoluble reaction with magnesium and other impurities. This feature makes it an essential ingredient in the production of nodular cast iron, and it also helps to improve the purity level of casting water by generating compounds that do not melt in the iron with Arsenic, Zinc, Tin, Lead and other impurities of lower melting points.
Elkem is introducing a new magnesium treatment practice that utilizes its LAMET nodulizer and TOPSEED cover alloy to treat molten iron for ductile-iron castings. The new process gives a quieter reaction, increases magnesium recoveries, and reduces costs. It will be demonstrated at the Elkem booth at CastExpo '13 in St. Louis April 6-9, 2013. The treatment results in lower scrap levels from shrinkage, better machinability, and higher strength in gray and ductile irons. It is particularly beneficial for small to medium-sized foundries.
English
Write a Message