Cr-Mo steel for high-temperature carburizing, carburizing method of Cr-Mo steel and carburizing component

Abstract

The invention relates to Cr-Mo steel for high-temperature carburizing, a carburizing method of the Cr-Mo steel and a carburizing component. The Cr-Mo steel for high-temperature carburizing comprises the following chemical components of, in percentage by weight, 0.13%-0.25% of C, less than or equal to 0.25% of Si, 0.55%-0.90% of Mn, less than or equal to 0.035% of P, 0.020%-0.040% of S, 0.85%-1.25% of Cr, 0.017%-0.037% of Al, 0.008%-0.015% of Ti, 0.040%-0.060% of Nb, less than or equal to 15ppm of O, 120ppm-170ppm of N, 0.010%-0.030% of Ni, 0.10%-0.20% of Cu, less than or equal to 0.06% of Mo, less than or equal to 0.04% of V, and the balance Fe and inevitable impurities. According to the Cr-Mo steel for high-temperature carburizing, when the carburizing temperature is larger than or equal to 980 DEG C, the grain size of a part is not larger than 7 grades; and according to the continuous furnace high-temperature carburizing method, the three-section preheating type and low-carbon potential diffusion high-temperature carburizing technology is adopted, high-efficiency carburizing of the part is achieved, on the premise that it is guaranteed that the carburizing layer depth of the part is 1.1-1.6 mm, the carburizing heat treatment period can be shortened to 13.2 h, the carburizing time is shortened to 7.2 h, and the carburizing efficiency is improved by 25%-30% relative to the carburizing efficiency at the temperature of 920-930 DEG C.

Description

technical field [0001] The invention belongs to the field of auto parts industry and metallurgy technology. The invention relates to a Cr-Mo steel used for high-temperature carburizing, a carburizing method, and carburizing parts. Background technique [0002] Cr-Mo series carburizing steel for domestic heavy-duty gearbox parts, national standard GB / T5216 stipulates material alloy element mass percentage (%): C0.17~0.23, Si0.17~0.37, Mn0.55~0.90, Cr 0.85~ 1.25, Mo 0.15~0.25 residual elements: P≤0.035, S≤0.035, Cu≤0.25, Ni≤0.30, the austenite grain size is not coarser than grade 5. [0003] The Cr-Mo series carburizing steel specified in the standard CGMA001~1 formulated by the China Gear Professional Association specifies the material alloy element mass percentage (%): C 0.18~0.23, Si 0.17~0.37, Mn0.40~0.70, Cr 0.80~1.10, Mo 0.15 ~0.25Al 0.02~0.05 Residual elements: P≤0.030, S S≤0.025, Cu≤0.30, Ni≤0.30, the austenite grain size is not coarser than grade 5. [0004] The ca...

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Problems solved by technology

[0005] In order to solve the problem that the existing Cr-Mo carburizing steel cannot meet the high-temperature carburizing requirements above 980°C, the present invention provides a Cr-Mo steel for high-temperature carburizing, its carburizing method, and carburizing parts

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