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1. (WO2018181862) METHOD FOR PRODUCING RAIL WHEEL AND RAIL WHEEL

Pub. No.:    WO/2018/181862    International Application No.:    PCT/JP2018/013538
Publication Date: Fri Oct 05 01:59:59 CEST 2018 International Filing Date: Sat Mar 31 01:59:59 CEST 2018
IPC: C21D 9/34
C22C 38/00
C22C 38/24
Applicants: NIPPON STEEL & SUMITOMO METAL CORPORATION
新日鐵住金株式会社
Inventors: MAEJIMA, Taketo
前島 健人
KUBOTA, Manabu
久保田 学
Title: METHOD FOR PRODUCING RAIL WHEEL AND RAIL WHEEL
Abstract:
The present invention makes it possible to consistently produce rail wheels for which generation of pro-eutectoid cementite has been curbed. In the invention, an intermediate product having 0.80 to 1.15% C in mass% is heated to an Acm transformation point or higher, and then cooled so that the rate of cooling (°C/sec) of the intermediate product from 800°C to 500°C meets the following conditions. Surfaces other than a tread surface and flange surface: ≤ Fn1 as defined in formula (1). Rate of cooling of a region where the rate of cooling is the slowest: ≥ Fn2 as defined in formula (2). Tread surface and flange surface: ≥ Fn2. Formula (1): Fn1=-5.0+exp(5.651-1.427×C-1.280×Si-0.7723×Mn-1.815×Cr-1.519×Al-7.798×V) Formula (2): Fn2=0.515+exp(-24.816+24.121×C+1.210×Si+0.529×Mn+2.458×Cr-15.116×Al-5.116×V)