Heat treatment process of bearing ring (3m) of shield tunneling machine

Abstract

The invention relates to a heat treatment process of a bearing ring (3m) of a shield tunneling machine. The method comprises the following steps: carrying out alloying design on an ordinary middle carbon alloy steel 42CrMo to obtain a steel meeting requirements of the bearing ring (3m) of the shield tunneling machine; heating a bearing ring blank produced by utilizing the steel to reach a certain temperature and carrying out heat preservation within a certain time, then carrying out oil cooling on the bearing ring blank until a room temperature reaches, carrying out high-temperature tempering on the bearing ring blank at a certain temperature and then carrying out heat preservation within a certain time, taking out the bearing ring blank and carrying out air cooling until a room temperature reaches; and carrying out induction heating on the surface of a machined bearing ring at a certain heating speed until a certain temperature reaches, and then quenching. After the experimental steel is treated by virtue of the process, the tissue of a hardening layer on the surface of the bearing ring of the shield tunneling machine is of cryptocrystalline martensite, and the matrix structure of the bearing ring is of tempered sorbite; the surface of the bearing ring is high in hardness, wherein the mean value of the hardness of the surface of the bearing ring is 57.9HRC; and the core part of the bearing ring is good in toughness and has proper hardness, wherein the mean value of the impact toughness Akv of the core part of the bearing ring at -20 DEG C is 115J, and the mean value of the hardness at the core part of the bearing ring is 293HB. Thus, the requirements of comprehensive mechanical properties of the steel for the bearing ring (3m) of the shield tunneling machine can be met.

Description

technical field [0001] The invention belongs to the field of metal materials, and relates to a heat treatment process for a 3m bearing ring of a shield machine, in particular to a component design and a heat treatment process for the comprehensive mechanical properties of steel used for a 3m bearing ring of a shield machine. Background technique [0002] At present, my country's economy is in a period of sustained and rapid development. Due to the needs of industrialization and infrastructure construction, a large number of traffic tunnels, urban underground railways, water supply and drainage tunnels, and cable tunnels have been built, are being repaired, or are being planned. The shield machine is the main construction machine in the shield construction. The bearing ring of the shield machine is the main part of the shield machine bearing. The service mode is low speed and heavy load. load and overturning moment. Therefore, on the basis of high fatigue strength, hardnes...

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Problems solved by technology

At present, there is no report on the steel used and the heat treatment process that meet the performance of the 3m bearing ring of the shield machine

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