Magnesium Ferrosilicon 5% 6% 7% for Spheroidizing Treatment and Nodular Cast Iron Production

Spheroidizing treatment is a controlled reaction, and the alloy is the control. Magnesium ferrosilicon 5% 6% 7% gives the treatment station three settings: a low-magnesium alloy for short, cool pours, a middle alloy for general work, and a high-magnesium alloy for sections that stay liquid long after the ladle is empty. Choose too low and the last metal poured comes out with flake graphite; choose too high and the heat boils at the surface, loses magnesium to the slag and arrives at the mould with dross. The three windows exist so a foundry can sit on the right side of that line without guessing.

Look at the station before the grade. A plunged bell in a deep ladle tolerates coarse lump and a higher magnesium level, because the alloy is held under the surface until it dissolves. A hand-shovelled pocket wants a smaller cut and a lower level, because the reaction is closer to the operator and less controllable. A cored-wire feed wants a fine, dry granule and a consistent bulk density, since the wire is filled by volume rather than by weight.

Then look at the heat. ZhenAn supplies all three windows from one grade list, so a station change does not force a supplier change. Sulphur in the base iron consumes magnesium before nodularization begins, so a high-sulphur charge needs either more alloy or a richer grade. Section thickness decides how much magnesium must remain after the pour. Holding time decides how much will be lost before the mould fills. A station that pours one ladle into twelve moulds is not the same problem as a station that pours one ladle into two.

Rare earth runs 1.0–3.0% on the 5% grade, 0.5–1.5% on the 6% grade and either 0.5–1.5% or 2.0–4.0% on the 7% grades. Aluminium stays at 1.0% or below on all three, and iron balances the alloy. Fractions are supplied from 0.25–2 mm through 1–5 mm to 5–20 mm, 10–30 mm and 10–50 mm, packed in 25 kg bags or 1000 kg jumbo bags.

• General engineering castings poured from a single treated ladle.
• Heavy frames and bases, where the alloy must survive a slow freeze.
• Thin-wall covers and housings, where an overshoot shows up as shrinkage.
• Fittings and small valves, poured in short runs from small ladles.
• Test coupons cut from production heats and checked for nodule count.

A plant that runs all five in one week should treat the grade as a per-heat decision, not a per-year one. The certificate format stays constant, so switching grade does not disturb the receiving process.

Put the magnesium band first, then the fraction, then the rare earth level, then the packing. Add the tonnage per shipment, the port and the delivery window, which the site states as 7–14 days from advance payment. Note the sampling method behind the certificate and whether a retained sample is expected.

Two items are commonly missed and cost time later. The first is the size tolerance: a fraction described only as lump can arrive anywhere from 5 to 100 mm, and a plunger bell will bridge on oversize. The second is the certificate cadence: per lot or per shipment. A per-shipment certificate covers a container, not the bags inside it.