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Heat treatment method capable of realizing both precipitation strengthening and lower bainite phase-transformation strengthening

A heat treatment method and precipitation strengthening technology, which is applied in the field of heat treatment that takes into account both precipitation strengthening and lower bainite transformation strengthening, and can solve the problems that precipitation strengthening and lower bainite strengthening cannot be solved

Active Publication Date: 2020-11-03
JIANGSU UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] The purpose of the present invention is to provide a heat treatment method that takes into account both precipitation strengthening and lower bainite transformation strengthening. The iron-based alloy prepared by the heat treatment method provided by the present invention has the characteristics of high hardness and high impact energy absorption, which effectively solves the existing problems. The defect that the heat treatment method in the technology cannot simultaneously carry out precipitation strengthening and lower bainite strengthening on the iron-based alloy

Method used

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  • Heat treatment method capable of realizing both precipitation strengthening and lower bainite phase-transformation strengthening
  • Heat treatment method capable of realizing both precipitation strengthening and lower bainite phase-transformation strengthening
  • Heat treatment method capable of realizing both precipitation strengthening and lower bainite phase-transformation strengthening

Examples

Experimental program
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Effect test

Embodiment 1

[0052] According to attached figure 1 The process curve in the heat treatment of H13 steel (brand, 4Cr5MoSiV1, see Table 1 for composition), the parameters of H13 steel are obtained from the TTT diagram of H13 steel, its Ac3 is 915 °C, and in the case of austenitization at 1050 °C, Ms is 320°C, Mf is 180°C, and the lower bainite transformation temperature range is 320°C to 400°C.

[0053] The heat treatment method is:

[0054] (1) Heating the H13 steel to 1050°C and holding it for 1 hour to obtain an austenitic alloy;

[0055] (2) cooling the austenitized alloy obtained in the step (1) to 260° C. and keeping it warm for 30 seconds to obtain a martensitic iron-based alloy;

[0056] (3) raising the temperature of the martensitic iron-based alloy obtained in the step (2) to 550° C. for 0.5 hours to obtain a tempered iron-based alloy;

[0057] (4) Water cooling the tempered iron-based alloy obtained in the step (3) to 340° C. for 2 hours, and then naturally cooling to room temp...

Embodiment 2

[0062] According to attached figure 1 The process curve in the heat treatment of 42CrMo steel (composition see Table 2), the parameters of 42CrMo steel are obtained from the TTT diagram of 42CrMo steel, its Ac3 is 800 ° C, in the case of austenitization at 840 ° C, its Ms is 310 ° C , Mf is 170°C, and the lower bainite transformation range is 310°C to 420°C.

[0063] The heat treatment method is:

[0064] (1) Heating 42CrMo steel to 840°C and holding it for 1 hour to obtain an austenitic alloy;

[0065] (2) cooling the austenitized alloy oil obtained in the step (1) to 200° C., and keeping it warm for 10 minutes to obtain a martensitic iron-based alloy;

[0066] (3) raising the temperature of the martensitic iron-based alloy obtained in the step (2) to 400° C. for 0.5 hours to obtain a tempered iron-based alloy;

[0067] (4) Cool the tempered iron-based alloy oil obtained in the step (3) to 340° C. for 2 hours, and then naturally cool to room temperature.

[0068] Properti...

Embodiment 3

[0073] According to attached figure 1 The process curve in the heat treatment of Cr12MoV steel (see Table 3 for composition), the parameters of Cr12MoV steel are obtained from the TTT diagram of Cr12MoV steel, its Accm is 855 ° C, it is austenitized at 1020 ° C, its Ms is 230 ° C, Mf The lower bainite temperature range is 230°C to 350°C.

[0074] The heat treatment method is:

[0075] (1) Heating the Cr12MoV steel to 1020°C and holding it for 1 hour to obtain an austenitic alloy;

[0076] (2) cooling the austenitized alloy oil obtained in the step (1) to 190° C., and keeping it warm for 1 minute to obtain a martensitic iron-based alloy;

[0077] (3) raising the temperature of the martensitic iron-based alloy obtained in the step (2) to 500° C. for 0.5 hours to obtain a tempered iron-based alloy;

[0078] (4) Cool the tempered iron-based alloy oil obtained in the step (3) to 240° C. for 2 hours, and then naturally cool to room temperature.

[0079] Properties of Cr12MoV ste...

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Abstract

The invention provides a heat treatment method capable of realizing both precipitation strengthening and lower bainite phase-transformation strengthening, and belongs to the technical field of heat treatment of alloy materials. The heat treatment method provided by the invention comprises the following steps that an iron-based alloy is heated to an austenite phase interval for first heat preservation, then cooled to the martensitic transformation temperature for second heat preservation, then heated up to the temperature interval where precipitation strengthening can be generated for third heat preservation, finally cooled into the temperature range of a lower bainite phase-transformation temperature interval for fourth heat preservation, and then cooled to the room temperature. The methodprocess of pre-quenching, tempering and lower bainite transformation is adopted, and precipitation strengthening, lower bainite phase-transformation strengthening and multi-phase (lower bainite and martensite) fine-grained strengthening are utilized to improve the strength and impact absorption energy of materials. The result of the embodiment shows that the hardness of the iron-based alloy prepared by the heat treatment method provided by the invention is greater than or equal to 56 HRC, and the impact absorption energy Aku of the iron-based alloy is greater than or equal to 28 J.

Description

technical field [0001] The invention relates to the technical field of heat treatment of alloy materials, in particular to a heat treatment method that takes into account both precipitation strengthening and lower bainite transformation strengthening. Background technique [0002] Due to their high strength and high hardness, iron-based alloys are often served under severe conditions of strong impact and strong wear, which may easily cause fracture of iron-based alloys. Therefore, it is often necessary to improve the performance of iron-based alloys. [0003] The heat treatment method is one of the most effective methods to improve the properties of iron-based alloys. The heat treatment method in the prior art is mainly quenching+tempering. [0004] Generally speaking, precipitation strengthening and lower bainite strengthening are not carried out on the same part, because after heat treatment to obtain lower bainite, if tempering treatment to promote precipitation strengthe...

Claims

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Application Information

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IPC IPC(8): C21D6/00C21D1/20C21D1/22
CPCC21D6/002C21D6/005C21D6/008C21D1/20C21D1/22C21D2211/002C21D2211/008
Inventor 袁志钟段旭斌张伯承韦家波罗锐程晓农
Owner JIANGSU UNIV
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