For austenitic stainless you need 8-10% nickel, and a village’s practical source is salvaged austenitic stainless itself, which already carries it; laterite and pentlandite ores come far behind because they need heavy processing. Skip nickel entirely if you must: ferritic stainless with chromium only still gives good corrosion resistance. Do not throw copper-nickel coins into a stainless melt, because they bring in roughly three parts copper to one of nickel.
Part of Stainless Steel Production
Where nickel for 300-series stainless can come from, and why salvage beats ore for a village.
Salvage Is The Nickel Source That Works
The carrier lists three sources: laterite ores, pentlandite, and salvage including stainless objects, nickel-plated items and coins. Of these, salvaged austenitic stainless is by far the most useful, because it is already the alloy you want. A sink, a saucepan or a milk can in the 8-10% nickel family contains the nickel and the chromium in the right balance. Remelting it is a better route than rebuilding the composition from ore. Sorting is covered in Metal Identification: austenitic pieces are non-magnetic or only weakly magnetic.
Ores Are A Distant Second
- Laterite ores: the carrier describes them as tropical weathered rock, often green-brown. Getting metal from laterite needs smelting or leaching at a scale I cannot source for a village, and I recall nickel grades of only one to two percent in laterite, which is unconfirmed.
- Pentlandite: a sulfide mineral in mafic rock per the carrier. Sulfide ores need roasting first, which brings the sulfur-dioxide hazard described in Pyrite Roasting.
The corpus has no article on producing nickel from either. The honest reading is that a village without salvaged stock does not make austenitic stainless.
Coins And Plating Are Poor Sources
The Phase 5 Advanced Materials article suggests coins “many contain 25% nickel”. A coin with 25% nickel is, as I recall of one common alloy, about 75% copper. Melting it into stainless would put three times as much copper into the melt as nickel. Copper does not belong in stainless, and it cannot be skimmed out afterward. Nickel plate is a thin skin on steel or brass, and the nickel yield per object is small. Treat both as emergency trace sources at best.
Worked Example
To reach 8% nickel in a 100 kg melt you need 8 kg of nickel. From pure nickel that is 8 kg. From a coin alloy at 25% nickel it is 8 / 0.25 = 32 kg of coins, which also bring 32 × 0.75 = 24 kg of copper, or 24% copper in the final 100 kg melt. The coin route fails on its own arithmetic.
Common Mistakes
- Counting nickel plate as a metal source. It is a surface coating.
- Using cupronickel scrap as “nickel”. It is mostly copper.
- Targeting austenitic grades without a nickel plan. If you have no salvage, make ferritic (Ferritic (400 Series)).
What’s Next
- Learn next: Austenitic (300 Series) - what the nickel buys
- Combine with: Alloy Addition Sequence - when the nickel goes in