With the comprehensive development and progress of medium and thick plate technology, people pay more attention to product quality, and manufacturing companies pay more attention to product quality, energy saving and other requirements. Comparing the advanced technology between our country and the world, it is easy to have many quality defects in production, which will have a serious negative impact on the quality of medium and thick plates, resulting in the need for extensive repairs during operations, which will greatly affect the entire production order, it will also cause the steel plate to be scrapped due to grinding, causing a certain amount of economic losses to the company and adversely affecting the development of the company.
Medium and thick plate heat treatment process
With the improvement of social productivity level, people's requirements for steel quality are gradually increasing. Adding a certain amount of alloying elements during the steel production process and then performing heat treatment can promote the improvement of the mechanical properties of the steel. The heat treatment of medium and thick plates mainly includes four aspects: normalizing, high temperature, quenching and tempering, and spheroidization.
1.1 Normalizing treatment
Normalizing treatment is also called normalizing treatment. The strength of medium and thick plates is usually relatively high, but the toughness is very low, so it should be normalized and then placed in the air to cool, so that fine gold particles will exist after cooling, medium and thick plate materials with a higher technical level can be obtained after normalization treatment.
1.2 High temperature treatment
High temperature treatment is also called tempering treatment. The main function of this treatment is to remove the stress existing inside the steel plate. It is obviously different from normalizing treatment. This aspect of treatment needs to ensure that the temperature is controlled within the Ac3 point.
1.3 Quenching and tempering treatment
The quenching and tempering treatment process is a combination of quenching and tempering. This treatment process has relatively high requirements for heat treatment. Heat treatment furnaces, low-temperature tempering furnaces and pressure quenching machines are necessary equipment. The martensite structure is formed during the production of medium and thick plates, which can be heated and tempered at low temperature. This is the entire process of quenching and tempering.
1.4 Spheroidization treatment
Spheroidization treatment is to form a spheroidized structure after the heating treatment of medium and thick plates. After the treatment is completed, the medium and thick plates can be used as tool steel plates, and the overall performance is relatively high.
In addition to the above-mentioned heat treatment processes, in specific production practices, technicians can optimize and integrate multiple aspects, and then form new heat treatment processes, such as normalizing-controlled cooling new processes and normalizing-tempering new processes. The function of the former is to avoid insufficient strength of the steel plate after normalizing treatment. After the steel plate is heat treated, water-cooling equipment can be used to achieve cold control treatment, which can prevent the strength of the steel plate from decreasing. In the heat treatment of boiler and pressure vessel steel plates, the normalizing-tempering heat treatment method has the best effect. When heat treating CrMo steel plates, normalizing-tempering technology can be used.
