A 1,000-Year-Old Precursor to Stainless Steel in Iran
Ancient Persians were forging alloys made from chromium steel, commonly referred to as stainless steel, some 1,000 years ago, according to a paper put out in September. The steel, made from 1% to 2% chromium and 2% phosphorus, was used to produce swords, daggers, armor, and other items. Technically speaking, these items weren’t stainless, and they were quite fragile (owing to the added phosphorus), but it’s now the earliest evidence of the intentional addition of a chromium mineral (in this case, chromite) to the crucible steel charge.
