The invention relates to CrMnTi narrow-
hardenability gear steel and a method for manufacturing the same, belonging to the gear steel material and the production process thereof technical field. The
chemical composition in percentage by weight of the gear steel is: 0.13-0.23 percent of C, 0.17-0.30 percent of Si, 0.80-1.25 percent of Mn, 0.04-0.10 percent of Ti, 0.90-1.35 percent of Cr, less than or equal to 0.20 percent of Cu, less than or equal to 0.050 percent of S, less than or equal to 0.030 percent of P, less than or equal to 0.05 percent of Mo, less than or equal to 0.25 percent of Ni, [O] less than or equal to 20x10<-6>, [H] less than or equal to 2.5x10<-6>, and the balance being Fe and inevitable impurities. The manufacturing method comprises the following process steps of
smelting,
continuous casting, rolling and hot rolling, wherein in the step of
continuous casting, the superheat degree of a
tundish is controlled between 10 and 30 DEG C, and the
casting speed is between 0.50 and 0.85 m / min; in the step of rolling, the
heating temperature is between 1130 and 1280 DEG C, the start rolling temperature is more than or equal to 1100 DEG C, and the finish rolling temperature is between 850 and 980 DEG C. The gear steel and round steel in the specification between phi 30 and 160 mm can be produced by adopting the manufacturing method. By adopting narrow-composition steel grade design, electric furnace burden structure optimization, electric furnace end point control, grain-refining and banded
structure control and other reasonable technological measures, the method effectively realizes
hardenability narrowing and other objectives.