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US 4,055,448 AGranted
Ferrite-austenite stainless steel
AssigneeDaido Seiko Kabushiki Kaisha
InventorsMasakuni Fujikura, Naohiro Abe
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AssigneeDaido Seiko Kabushiki Kaisha
InventorsMasakuni Fujikura, Naohiro Abe
Estimating the term…
Disclosed is an improved stainless steel in ferrite-austenite condition caused by solution heat treatment at a temperature of 1000.degree. - 1150.degree. C, composed of by weight percent, carbon up to 0.06%, silicon up to 1.0%, manganese up to 1.5%, nickel from 3.0% to 7.0%, chromium from 21.0% to 28.0%, copper up to 3.0%, molybdenum from 1.0% to 4.0%, boron from 0.0008% to 0.0080%, niobium from 0.08% to 0.7%, titanium from 0% to 0.5%, tantalum from 0% to 0.5%, zirconium from 0% to 0.5%, nitrogen up to 0.1%, and the remainder of iron and an inevitable amount of impurity, with the values of nickel equivalent and chromium equivalent calculated by the following equations: Nickel equivalent = 40(carbon % + nitrogen %) + 3(nickel %) + (copper %) + 2(manganese %) Chromium equivalent = (chromium %) + 5.2(silicon %) + 4.2(molybdenum %) + 4.5(niobium %) + 7.0(titanium %) + 3.0(tantalum %) + 13.0(zirconium %) Satisfying the relationship below: Nickel equivalent = from 15 to 30 Chromium equivalent = from 28 to 50 Chromium equivalent -- nickel equivalent = from 8 to 27.
An improved stainless steel in ferrite-austenite condition said ferrite-austenite condition being produced by solution heat treatment at a temperature of 1000 .degree. -1150 .degree. C, and composed of, by weight percent, carbon up to 0.06%, silicon up to 1.0%, manganese up to 1.5%, nickel from 3.0% to 7.0%, chromium from 21.0% to 28.0%, copper up to 3.0%, molybdenum from 1.0% to 4.0%, boron from 0.0008% to 0.0080%, niobium from 0.08% to 0.7%, titanium from 0% to 0.5%, tantalum from 0% to 0.5%, zirconium from 0% to 0.5%, nitrogen up to 0.1%, and the remainder of iron and an inevitable amounts of impurity, with the values of nickel equivalent and chromium equivalent calculated by the following equations:
An improved stainless steel in ferrite-austenite condition, said ferrite-austenite condition being produced by solution heat treatment at a temperature of 1000 .degree. -1150 .degree. C, and composed of, by weight percent, carbon up to 0.06%, silicon up to 1.0%, manganese up to 1.5%, nickel from 3.0% to 7.0%, chromium from 21.0% to 28.0%, copper from 0.8% to 2.0%, molybdenum from 1.0% to 4.0%, boron from 0.0008% to 0.0080%, niobium from 0.08% to 0.7%, titanium from 0% to 0.5%, tantalum from 0% to 0.5%, zirconium from 0% to 0.5%, nitrogen up to 0.1%, and the remainder of iron and an inevitable amounts of impurity, with the values of nickel equivalent and chromium equivalent calculated by the following equations:
Dependencies are inferred from the claim text.