A carburizing and quenching method for heavy-duty gears

Abstract

The invention discloses a heavy-duty gear carburizing and quenching method, and relates to the technical field of special steel making. The method comprises the following steps that a gear workpiece is subjected to carburizing treatment in a gas carburizing furnace, and then is subjected to austenitizing heating thermal insulation after getting out of furnace; then the gear workpiece is subjectedto precooling quenching; the gear workpiece is subjected to water-base medium quenching, salt bath quenching and fog cooling in sequence; and the gear workpiece is washed after fog cooling is finished, and then is subjected to tempering treatment. With the heavy-duty gear carburizing and quenching method, the problem that for a large-control-section gear made of a low-hardenability material, a quenching method in the prior art cannot achieve the purposes of making the performance of a center part and a gear root excellent and having effectively control over stress type cracking at the same time is solved, it is achieved that a heavy-duty gear is controllable in carburizing and quenching deformation without cracks, and the hardness, the texture, a hardened layer and the dynamic performanceof the heavy-duty gear all meet the technological design requirements.

Description

technical field [0001] The application relates to the technical field of special steel manufacturing, in particular to a carburizing and quenching method for heavy-duty gears. Background technique [0002] Chromium-manganese-nickel series low-hardenability carburizing steel has high plasticity and toughness. Due to the relatively low alloy content, its hardenability is relatively poor. Gears are mainly used for modulus below 8. Because of its relatively low alloy content, its raw materials The price advantage is obvious, so it has also been applied in the field of large-module heavy-duty gears. The large-scale heavy-duty gear manufacturing industry has high requirements for core hardness and structure. Chromium-manganese-nickel series low-hardenability carburizing steel materials exist The disadvantage is that the hardenability is relatively poor, so the key point of the control of the large and heavy-duty gear manufacturing industry is the core performance. [0003] The qu...

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Problems solved by technology

[0004] The embodiment of the present application provides a carburizing and quenching method for heavy-duty gears, which solves the problem that the existing quenching methods for gears made of materials with large control sections and low hardenability cannot simultaneously achieve excellent performance at the center and root and effectively control stress-type cracking , to achieve controllable carburizing and quenching deformation without cracks, and the hardness, structure, hardened layer, and mechanical properties all meet the process design requirements

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