IMTI-LC

For Gray and Compacted Graphite Cast Irons

IMTI - LC is a unique ferrosilicon inoculant containing calcium and titanium for nucleation and graphitization, while the titanium content also combines with nitrogen in iron to reduce incidence of fissure-type porosity.

IMTI - LC minimizes the formation of chill during solidification by improving nucleation in the molten phase. The large number of nuclei created by adding this alloy results in a uniform matrix structure with the desired type and size of graphite. This assures the best combination of mechanical properties and machinability.

Nitrogen fissure defects can be a problem to foundrymen when nitrogen levels in cast iron exceed 80-100 parts per million, especially in heavier section sizes. Nitrogen is dissolved in the iron during the melting process, and may increase even further as the molten metal comes in contact with certain types of cores and molds employing nitrogen bearing chemical binder systems. As the metal solidifies, solubility of nitrogen decreases, and it is rejected from the melt. If unable to escape through the surface of the casting, the gas remains in the form of fissures. Adding two to four pounds per ton of IMTI - LC can eliminate these defects by tying up the excessive nitrogen as tiny, harmless titanium nitride particles. Higher addition rates of IMTI - LC - above six pounds per ton, can cause a marked decline in tensile strength as a result of excess titanium promoting the formation of Type D graphite and associated ferritic areas. (Some foundries have actually used this to their advantage!) Properly added, however, IMTI - LC significantly improves mechanical properties.

In Compacted Graphite (CG) Irons: IMTI - LC allows an accurate and consistent amount of titanium to be added during the inoculation process, providing closer control of titanium residuals. Because of the dilute concentration of titanium in this alloy, titanium recoveries in the iron will approach 90%. Commercial tonnages of CG iron have been produced by utilizing a regular type of 5% magnesium-ferrosilicon in combination with a 0.8% addition of IMTI - LC; 0.5% as cover for the nodulizer, and 0.3% as post-inoculant.

Effective Date: 1/28/13