Heat treatment carburizing process of carburizing steel

A carburizing steel and carburizing technology, which is applied in the field of heat treatment of metal materials, can solve problems such as the inability to meet the service performance requirements, and achieve the effects of avoiding carbide coarsening, increasing carbide size, and improving wear resistance.

CN104726819BActive Publication Date: 2017-09-19SHANGHAI C&U GRP CO LTD +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2017-09-19

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Abstract

The invention relates to a heat treatment carburization process of carburizing steel. The heat treatment carburization process orderly comprises the following steps: pre-carburization (under the conditions of the temperature of 800-840 DEG C, the carbon potential of 0.9-1.3 and the time of 1-3 hours); circulating carburization (under the conditions of the temperature of 910-940 DEG C, the carbon potential of 0.9-1.3 and the time of 1-4 hours, cooling in an oil at the temperature of 50-140 DEG C, and circulating twice); diffusing and quenching (carburizing for diffusion under the conditions of the temperature of 910-940 DEG C, the carbon potential of 0.8-1.0 and the time of 1-3 hours, reducing the temperature to the range of 840-890 DEG C after diffusion, and after retaining the heat at the carbon potential of 0.8-1.0 for 0.5-2 hours, quenching and cooling in the oil at the temperature of 50-140 DEG C); and tempering (at 160-230 DEG C for 2-4 hours). According to the heat treatment carburization process, the special pre-carburization process is added and matched with the circulating carburization, so that lots of fine carbide particles can be formed in the surface carburized layer; the grain size is thinned to grade 9 from grade 7 and the surface wear resistance is greatly improved on the basis of satisfying the properties of the core.
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Description

technical field

[0001] The invention relates to a heat treatment process for metal materials, specifically a heat treatment and carburization process for carburized steel. Background technique

[0002] Due to the particularity of the working environment of bearing parts, many bearings have requirements for wear resistance while being able to withstand impact loads.

[0003] In order to meet the requirements of the above working conditions, the bearing needs the material (carbon steel) to be carburized and heat treated; carburizing: it is a kind of metal surface treatment, so that the activated carbon atoms decomposed in the carburizing medium penetrate into the surface of the steel part, In order to obtain high carbon on the surface, the heart still maintains the original composition. This is a common heat treatment process for metal materials, which can make the surface of the carburized workpiece obtain high hardness and improve its wear resistance.

[0004] In conventio...

Examples

Embodiment 1

[0025] according to image 3 The process curve diagram proceeds:

[0026] (1) Pre-carburization: 1h pre-carburization at 830°C and carbon potential 1.1;

[0027] (2) Cyclic carburizing: use 920°C, carbon potential 1.1, carry out carburizing for 3 hours, and then cool in oil at 100°C; after that, use 920°C, carbon potential 1.1, carry out carburizing for 3 hours, and then in 100°C The process step of cooling in oil is cycled once to complete the cyclic carburizing with 2 cycles;

[0028] (3) Diffusion and quenching: Use 920°C, carbon potential 1.0, and carry out carburizing diffusion for 2 hours to obtain a gentle carbon concentration distribution and reduce the stress caused by carburizing heat treatment; after diffusion, cool the temperature to 860°C, carbon potential 1.0, after holding for 1 hour, quench and cool in oil at 100°C;

[0029] (4) Tempering: Tempering at 180°C for 3 hours.

[0030] After completion, use the peeling method to detect the carbide content on the ...

Embodiment 2

[0032] according to Figure 4 The process curve diagram proceeds:

[0033] (1) Pre-carburization: 800°C, carbon potential 0.9, 2h pre-carburization;

[0034] (2) Cyclic carburizing: use 910°C, carbon potential 0.9, carry out carburizing for 1h, and then cool in oil at 50°C; after that, use 910°C, carbon potential 0.9, carry out carburizing for 1h, and then in 50°C The process step of cooling in oil is cycled once to complete the cyclic carburizing with 2 cycles;

[0035] (3) Diffusion and quenching: use 910°C, carbon potential 1.0, and carry out carburizing diffusion for 2 hours to obtain a gentle carbon concentration distribution and reduce stress caused by carburizing heat treatment; after diffusion, cool the temperature to 860°C, carbon potential 1.0, after holding for 1 hour, quench and cool in oil at 100°C;

[0036] (4) Tempering: Tempering at 180°C for 3 hours.

[0037] After completion, use the peeling method to detect the carbide content on the surface: the carbide...

Embodiment 3

[0039] according to Figure 5 The process curve diagram proceeds:

[0040] (1) Pre-carburization: 840°C, carbon potential 1.3, 3h pre-carburization;

[0041] (2) Cyclic carburizing: use 940°C, carbon potential 1.3, carry out carburizing for 4 hours, and then cool in oil at 130°C; after that, use 940°C, carbon potential 1.3, carry out carburizing for 4 hours, and then in 130°C The process step of cooling in oil is cycled once to complete the cyclic carburizing with 2 cycles;

[0042] (3) Diffusion and quenching: use 940°C, carbon potential 1.0, and carry out carburizing diffusion for 2 hours to obtain a gentle carbon concentration distribution and reduce stress caused by carburizing heat treatment; after diffusion, cool the temperature to 900°C, carbon potential 0.8, after holding for 1 hour, quench and cool in oil at 100°C;

[0043] (4) Tempering: Tempering at 180°C for 3 hours.

[0044] After completion, use the peeling method to detect the carbide content on the surface:...