IM 75-B

A Potent Inoculant for Gray and Ductile Cast Irons

In Gray Iron: Recent literature has shown once again that effects obtained from the combined addition of two alloying elements are often greater than the added effects of the individual elements. This same type of synergistic effect has long been recognized with regard to the role of Calcium and Barium in cast iron inoculation. The combination of Calcium and Barium in IM 75-B provides a potent nucleating effect with about 40% less IM 75-B needed to obtain equivalent chill depths produced by the use of standard inoculating grade ferrosilicons. At similar addition rates, IM 75-B produced dramatically lower chill depths than standard inoculants, at all Carbon equivalent levels.

IM 75-B is particularly useful in higher strength, 3.6-3.8 Carbon equivalent irons, in which inoculation would be expected to have the greatest effect on improvement of mechanical properties. The combination of Calcium and Barium minimizes undercooling, and promotes eutectic solidification with Type A graphite and a pearlitic matrix. The comparatively high Silicon content of this alloy further serves to increase eutectic cell count, ensuring optimum properties from a given Iron analysis. Because the alloy is based on 75% ferrosilicon, its reaction with liquid iron is exothermic, ensuring excellent dissolution and consistency of results.

In Ductile Iron: Alloys containing over 70% silicon have long been the favored inoculation material for ductile iron. In special carbideprone work, many commercial foundries have reported increased nucleation and elimination of chill because of the more potent effect of Calcium plus Barium. During a two day trial in a commercial foundry comparing a Calcium plus Barium alloy a regular Calcium bearing ferrosilicon and a high Aluminum European inoculant, the Calcium plus Barium alloy produced nodule counts 18% higher than either of the other two alloys.

IM 75-B can be used in all grades of ductile iron.

IM 75-B is produced in state-of-the-art submerged arc furnaces in one of the newest ferrosilicon plants in the world, completed in 1980. By using charcoal and iron ore in place of metallurgical coke and steel scrap as reducing agent and iron unit source, respectively, residual levels of harmful tramp elements are controlled to extremely low levels. The manufacturing operation is supported by an in depth quality program devoted to problem prevention through the application of statistical control techniques. This is a unique combination of modern facility and quality attitude aiming to provide products that consistently conform to specific customer requirements.

Effective Date: 3/28/06