Stainless steel is made by melting low-carbon steel at about 1,600 °C in an electric arc furnace, lowering its carbon, and then adding ferrochrome, plus nickel for austenitic grades, until the chromium reaches 12-18%. A village has three routes: remelt salvaged stainless, build ferritic or martensitic grades from ferrochrome, or attempt full low-carbon grades, which need refining that this tree cannot source for village scale.
Part of Stainless Steel Production
The furnace stage of stainless-steel making: melting a base charge, controlling carbon, and adding chromium and nickel.
The Carrier’s Sequence Is Seven Steps In One Order
The carrier lists the sequence for a 50-200 kg batch: charge steel scrap, strike the arc and melt at about 1,600 °C, decarburize by blowing air or oxygen through the melt, add ferrochrome once carbon is low to reach the target chromium of 12-18%, add nickel for austenitic grades, sample and adjust, then tap and cast. The order is deliberate: the carrier notes that chromium inhibits further carbon removal, and as I recall chromium is also oxidised into the slag when you blow a melt that already contains it, so the carrier decarburises first and adds chromium last. The other steps in this tree take that sequence apart: EAF Operation for Stainless, Carbon Control and Alloy Addition Sequence.
Three Routes, Honestly Ranked
| Route | What goes in | What you can realistically get | Main obstacle |
|---|---|---|---|
| Remelt salvaged stainless | Sinks, cookware, instruments, sorted | The same family of stainless again | A crucible and furnace that hold about 1,400-1,500 °C (recalled melting range) |
| Add ferrochrome to low-carbon steel | Steel scrap, ferrochrome | Ferritic and martensitic grades at moderate carbon | Carbon carried in by the ferrochrome |
| Full low-carbon grades with nickel | All of the above plus nickel | Austenitic grades | Needs both low carbon and a nickel supply |
The first row skips the ore entirely and is the practical default. Crucibles puts iron-melting crucibles at 1-3 melts before replacement, and stainless sits in the same temperature neighbourhood, so even this route costs crucibles.
What You Need
- A furnace that melts steel: the arc furnace of EAF Operation for Stainless, or at minimum a blown crucible furnace for remelting small charges.
- Dry, clean, sorted charge. Wet scrap is the most dangerous thing you can put into a furnace.
- Alloying metals: ferrochrome (Ferrochrome Production) and nickel (Nickel Sources).
- Moulds or a ladle, preheated and dry.
Worked Example
A 100 kg melt of 17% chromium needs 17 kg of chromium. From 65% ferrochrome (the midpoint of the carrier’s 60-70%), the alloy added is 17 / 0.65 = 26 kg, so about 74 kg of the batch is base steel. Chromium lost to oxidation or slag would raise the ferrochrome needed; I have no figure for the loss.
Common Mistakes
- Adding ferrochrome first and then blowing for carbon. The chromium burns out into the slag.
- Charging coated or wet scrap. Paint, plating and water ruin analysis and endanger the crew.
- Not weighing the charge. No method in the corpus measures chromium percentage in the finished steel, so the arithmetic above is the only control. Spark and acid spot tests are rough.
Safety
Molten steel at 1,600 °C
Water or damp scrap in a molten charge turns to steam instantly and throws the melt; a cold or damp mould does the same. Dry and preheat every charge piece, tool, ladle and mould, and stand clear of the pour. Furnace fume carries chromium compounds (see Why Stainless Steel). Electrical hazards are in EAF Operation for Stainless.
What’s Next
- Learn next: EAF Operation for Stainless - running the furnace
- Combine with: Achievable Grades - choosing the target composition