UA84987C2 - Bainite steel for solid-rolled railway wheels (variants) and method for heat treatment of solid-rolled railway wheels from bainite steel - Google Patents

Abstract

The group of inventions relate to ferrous metallurgy, namely to composition of bainite steel for solid-rolled rail way wheels and to method for heat treatment thereof. A bainite steel contains, w/w: carbon – 0.12-0.129, manganese – 1.02-1.5, silicon – 0.24-0.32, chromium – 0.37-3.5, nickel – 0.01-1.95, aluminium – 0.03-0.05, titanium – 0.03-0.04, molybdenum – 0.05-1.2, vanadium – 0.01-0.02, iron – other. In the second variant composition this steel contains, w/w: carbon – 0.32-0.45, manganese – 0.95-1.3, silicon – 0.7-0.83, chromium – 2.0-2.3, nickel – 0.01-0.02, molybdenum – 0.26-1.0, vanadium – 0.01-1.1, other elements of composition have similar intervals of the contents, as well as in the first variant. A method heat treatment of solid-rolled wheels comprises their continuous cooling on air from temperature rolling to room temperature, heating and quenching from temperature 820-950 °С with rate of cooling 10 °С/s, then is carried out tempering at temperature 500-525 °С. The group of invention provides increasing of mechanical and operational characteristics: impact strength at 20 °С KCU to 27.85-55.6 J/sm, hardness to 400-460 НВ, strength limitsto 1300-1610 МPa, yield strengthto 1080-1389 МPа, percent elongationto 8-13.9 %contraction ratioto 14-45,6 %, wear resistance in 1.2-1.6 times, resistance against martensate transformations at emergency and long brake application in operating conditions.