When steel is quenched using a medium frequency induction heating power supply, what effect do the various elements in the steel have on the induction quenching of the steel?

In order to improve the wear resistance, hardness and service life of the steel plate, we usually use medium frequency induction heating power to perform induction quenching heat treatment on the steel plate. The quality of the heat treatment is affected by many factors. Among them, various elements in the steel have an impact on the quality of the steel plate heat treatment. It has a great influence. Next, we will tell you one by one what effect each element in steel has on induction quenching of steel plates.

(1) Carbon. Carbon determines the hardness that can be achieved after quenching of steel. High carbon content results in high quenching hardness, but it is easy to crack during quenching. Generally, the carbon content is 0.30%-0.50%, and the hardness value obtained is about 50-60HRC. The upper limit of the hardness value is restricted by the carbon content. Practice has proven that this carbon content is about 0.50%. Higher carbon contents are sometimes used, for example rolls are made of steel with 0.80% carbon, 1.8% carbon and 0.25% carbon. Carbon steel that does not contain alloy elements requires a high cooling rate, so it has a large deformation and a tendency to crack. In addition, its hardenability is also poor.

(2) Manganese. Manganese in steel improves the hardenability of steel and reduces the critical cooling rate. Manganese forms a solid solution in ferrite when heated, which can improve the strength of steel. Manganese steel is commonly used when the depth of the hardened layer is greater than 4mm. Because it reduces the critical cooling rate, the cooling specification is less stable. Uniform quenching hardness can be obtained.

(3) Silicon. In addition to improving the strength and hardenability, the silicon in steel can also remove gases from the steel during steelmaking and act as a sedative.

(4) Sulfur. Sulfur in steel will form sulfides. Tests have shown that when the sulfur content is reduced, the elongation and area reduction are improved, and the impact toughness value increases.

(5)Molybdenum. Molybdenum in steel can improve hardenability, and the content of molybdenum in steel is very small.

(6) Phosphorus. Phosphorus in steel does not form phosphide, but it easily causes severe segregation, so it is a harmful element.

(7) Chromium. Since chromium in steel can form carbides, it is necessary to increase the heating temperature and extend the heating time, which is detrimental to induction hardening. However, chromium improves the hardenability of steel (similar to manganese), and chromium steel has higher mechanical properties in the quenched and tempered state. Therefore, 40Cr and 45Cr are often used to manufacture heavy-duty gears and splined shafts. The carbon content in steel induction hardened with a medium frequency heating power supply generally does not exceed 1.5%, and the maximum does not exceed 2%. Under special circumstances, induction quenching can also be performed when the carbon content is below 17%, but a very high heating temperature is required. The heating temperature is below 1200°C. At this time, the carbide will dissolve quickly and it can be fully quenched.

Various elements in steel have a great influence on the quality of heat treatment of steel induction quenching. Therefore, we must be careful when selecting materials. Zhengzhou Gao's is a manufacturer specializing in the production of medium frequency heating power supplies. It is very familiar with the heat treatment of workpieces. If you want to know more information that affects the quality of heat treatment, you can call us for consultation.