阅读说明：本技术 一种高强汽车用钢组织细化的热处理方法 (Heat treatment method for refining steel structure of high-strength automobile ) 是由 王永强 黎俊良 李娜 张志伟 孙浩 黄飞 朱国辉 陈其伟 于 2019-11-18 设计创作，主要内容包括：本发明公开一种高强汽车用钢组织细化的热处理方法,包括以下步骤；将高强汽车用钢板放入热处理炉中；进行930℃～950℃加热温度的淬火处理,完成淬火处理后,进行600℃～630℃加热温度的回火处理；重复若干次所述淬火处理和所述回火处理；本发明所需设备简单、易于操作、效果好,能实现不同成分钢铁材料的组织细化。(The invention discloses a heat treatment method for refining a steel structure for a high-strength automobile, which comprises the following steps of; putting the high-strength automobile steel plate into a heat treatment furnace; quenching at 930-950 ℃, and tempering at 600-630 ℃ after quenching; repeating the quenching treatment and the tempering treatment several times; the method has the advantages of simple required equipment, easy operation and good effect, and can realize the tissue refinement of steel materials with different components.)

1. A heat treatment method for refining a steel structure for a high-strength automobile is characterized by comprising the following steps;

s1, placing the high-strength automobile steel plate into a heat treatment furnace;

s2, quenching treatment is carried out at the heating temperature of 930-950 ℃;

s3, after the step S2 is finished, tempering treatment is carried out at the heating temperature of 600-630 ℃;

s4, repeating the step S2 and the step S3 several times.

2. The heat treatment method for structure refinement of a high strength automobile steel according to claim 1, wherein the steel sheet for a high strength automobile is a C-Mn-Cr steel sheet.

3. The heat treatment method for tissue refinement of high strength automobile steel according to claim 2, wherein in step S2, the heating temperature of the quenching treatment is 930 ℃ to 950 ℃, the heating rate is 10 ℃/S, the quenching heat preservation time is 5min to 10min, the cooling manner of the quenching treatment is water cooling, and the cooling rate is 20 ℃/S to 25 ℃/S.

4. The heat treatment method for tissue refinement of high strength automobile steel according to claim 3, wherein in step S3, the heating temperature of the tempering treatment is 600 ℃ to 630 ℃, the heating rate is 5 ℃/S, the tempering heat preservation time is 5min to 15min, the cooling mode of the tempering treatment is air cooling, and the cooling rate is 5 ℃/S to 8 ℃/S.

5. The heat treatment method for tissue refinement of high strength automotive steel according to claim 1, characterized in that the heat treatment furnace is a box-type resistance furnace, a tube-type resistance furnace or a vacuum annealing furnace, and the isothermal heat treatment atmosphere is air, vacuum or inert gas.

6. The heat treatment method for tissue refinement of steel for a high strength automobile according to claim 4, wherein the step S2 and the step S3 are repeated twice in the step S4.

7. The heat treatment method for the structure refinement of the steel for the high-strength automobile according to claim 2, wherein the quenching treatment for the first time is a quenching treatment in which the heating temperature is 950 ℃ and the temperature is maintained for 10 min; the tempering treatment for the first time adopts the tempering treatment of keeping the temperature at 630 ℃ for 15 min; the second quenching treatment adopts the quenching treatment of keeping the temperature at 930 ℃ for 10 min; the second tempering treatment adopts the tempering treatment of keeping the temperature for 15min at the heating temperature of 600 ℃; the third quenching treatment adopts the quenching treatment of keeping the temperature at 930 ℃ for 5 min; the third tempering treatment adopts the tempering treatment of keeping the temperature at 600 ℃ for 10 min.

Technical Field

The invention relates to the technical field of steel material processing, in particular to a heat treatment method for refining a steel structure for a high-strength automobile.

Background

The steel material is the most widely applied metal structural material at present, and along with technological progress and social development, people have higher and higher requirements on the performance of the steel material. The tissue refinement is the only method which can improve the strength and the plasticity and toughness at present. There are many methods for refining the metal structure, including; the nucleation rate is increased by adding a non-uniform nucleating agent from the metallurgical (solidification) point of view, the nucleation rate is increased by electromagnetic stirring in the solidification process, and the like; large plastic deformation (SPD) techniques from a physical metallurgical point of view, such as equal channel angular extrusion (ECAP/ECAE), cumulative lap rolling (ARB), High Pressure Torsion (HPT), etc., and advanced thermomechanical treatment techniques (also known as mechano-ATMP), such as controlled rolling controlled cooling (TMCP), deformation induced ferrite phase transformation (DIFT), strain induced dynamic phase transformation (SIDT), etc.

Although the SPD technology can refine grains to nanometer size, it is difficult to scale up due to the complexity of the process and high requirements of the equipment. While the thermomechanical treatment technology represented by the TMCP technology can be used for industrial production, it has specific requirements for steel grade components and large equipment investment. Although the method for controlling the metal solidification process from the metallurgical perspective is an effective method for refining the structure, the method belongs to the upstream stage of metal preparation, and the final structure is difficult to determine whether the structure of the final product is refined or not because the production flow of the steel material is long and each subsequent process influences the final structure.

In view of the above-mentioned drawbacks, the inventors of the present invention have finally obtained the present invention through a long period of research and practice.

Disclosure of Invention

In order to solve the technical defects, the technical scheme adopted by the invention is to provide a heat treatment method for refining a high-strength automobile steel structure, which comprises the following steps;

s1, placing the high-strength automobile steel plate into a heat treatment furnace;

s2, quenching treatment is carried out at the heating temperature of 930-950 ℃;

s3, after the step S2 is finished, tempering treatment is carried out at the heating temperature of 600-630 ℃;

s4, repeating the step S2 and the step S3 several times.

Preferably, the high-strength steel plate for the automobile is a C-Mn-Cr steel plate.

Preferably, in the step S2, the heating temperature of the quenching treatment is 930 ℃ to 950 ℃, the heating rate is 10 ℃/S, the quenching heat preservation time is 5min to 10min, the cooling manner of the quenching treatment is water cooling, and the cooling rate is 20 ℃/S to 25 ℃/S.

Preferably, in the step S3, the heating temperature of the tempering treatment is 600 ℃ to 630 ℃, the heating rate is 5 ℃/S, the tempering heat preservation time is 5min to 15min, the tempering cooling mode is air cooling, and the cooling rate is 5 ℃/S to 8 ℃/S.

Preferably, the heat treatment furnace is a box-type resistance furnace, a tube-type resistance furnace or a vacuum annealing furnace, and the isothermal heat treatment atmosphere is air, vacuum or inert gas.

Preferably, in the step S4, the step S2 and the step S3 are repeated twice.

Preferably, the first quenching treatment adopts the quenching treatment of keeping the heating temperature at 950 ℃ for 10 min; the tempering treatment for the first time adopts the tempering treatment of keeping the temperature at 630 ℃ for 15 min; the second quenching treatment adopts the quenching treatment of keeping the temperature at 930 ℃ for 10 min; the second tempering treatment adopts the tempering treatment of keeping the temperature for 15min at the heating temperature of 600 ℃; the third quenching treatment adopts the quenching treatment of keeping the temperature at 930 ℃ for 5 min; the third tempering treatment adopts the tempering treatment of keeping the temperature at 600 ℃ for 10 min.

Compared with the prior art, the invention has the advantages that; the method has the advantages of simple required equipment, easy operation and good effect, and can realize the tissue refinement of steel materials with different components.

Drawings

FIG. 1 is a metallographic structure of samples according to one example;

FIG. 2 is a graph comparing the average grain sizes of samples of one example;

FIG. 3 is a graph comparing the average Rockwell hardness of samples from one example;

FIG. 4 is a metallographic structure drawing of samples obtained by the second example;

FIG. 5 is a comparison of the average grain sizes of the samples of the second example;

FIG. 6 is a graph comparing the average Rockwell hardness of the samples of the second example;

FIG. 7 is a metallographic structure drawing of a sample of each of the three samples according to example;

FIG. 8 is a comparison of the average grain sizes of the three samples of the example;

FIG. 9 is a graph comparing the average Rockwell hardness of three samples of example.

Detailed Description

The above and further features and advantages of the present invention are described in more detail below with reference to the accompanying drawings.