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Stainless steel was developed in Sheffield in 1913 by Harry Brearley, a metallurgist trying to stop gun barrels wearing away. As the story is often told, weeks after throwing out his failed samples he noticed that one of them, on the scrap heap, had not rusted.

Sheffield, 1913

TechnologyHistory

The story behind the card

Brearley left school at twelve to work as a labourer in a steelworks and taught himself chemistry and metallurgy at home and in evening classes. At the Brown-Firth laboratories he was testing steels with added chromium when, in August 1913, he cast one containing 12.8 per cent chromium. What he recorded himself is less dramatic than the scrap-heap story: the new steel resisted the acids used to etch samples for the microscope. Chromium forms a thin, invisible oxide layer that seals the surface. When vinegar and lemon juice did not stain it either, he thought of Sheffield's cutlery trade rather than guns. He called it 'rustless steel'; the name 'stainless steel' came from Ernest Stuart of the Sheffield cutlery firm R. F. Mosley.

Türkçe oku
Paslanmaz çeliği 1913'te Sheffield'da metalürji uzmanı Harry Brearley geliştirdi; aslında top namlularının çabuk aşınmasına çare arıyordu. Sık anlatılan hikâyeye göre Brearley, başarısız saydığı örnekleri hurdaya attıktan haftalar sonra birinin hiç paslanmadığını fark etti.
Sheffield, 1913

Brearley okulu on iki yaşında bırakıp bir çelik fabrikasında işçi olarak çalışmaya başladı; kimyayı ve metalürjiyi evde ve akşam kurslarında kendi kendine öğrendi. Brown-Firth laboratuvarlarında kromlu çelikleri denerken, Ağustos 1913'te yüzde 12,8 krom içeren bir çelik döktü. Kendi notlarında anlattığı olay, hurda yığını hikâyesinden daha sadedir: Yeni çelik, mikroskop için numuneleri aşındırmakta kullanılan asitlere direnç gösteriyordu. Bunun nedeni, kromun yüzeyi kapatan ince ve görünmez bir oksit tabakası oluşturmasıdır. Sirke ve limon suyu da çeliği lekelemeyince Brearley'nin aklına silahlar değil, Sheffield'ın ünlü çatal bıçak sanayisi geldi. Çeliğe “pas tutmaz çelik” adını verdi; “paslanmaz çelik” adı ise Sheffield'daki çatal bıçak üreticisi R. F. Mosley'den Ernest Stuart'ın önerisiydi.

Sources and further reading

Background reading: Harry Brearley
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