TREATMENT OF STEEL WITH ALKALINE-EARTH ELEMENTS

To evaluate the potential benefits of strontium treatment of steel com pared to calcium, steel-clad wires of calcium-silicon, calcium and str ontium were fabricated. Lengths of these wires were injected to 35 kg heats of AlSl 1045 steel. Samples for total calcium or strontium, oxyg en, sulphur, and aluminum were taken as frequently as possible during and after the injection. The recoveries of the alkaline-earth elements in steel for the three wires were 8.3, 4.6 and 0.41%, respectively. T here was virtually no inclusion modification with the strontium wire c ompared to the calcium-containing wires. It was found that the absorpt ion rate of the alkaline-earth elements increased with the sulphur and oxygen contents of the steel. A mathematical model for this enhanced dissolution rate was developed which identifies the fundamental limita tions of the alkaline-earth elements for steel treatment.