The advantages and shortcomings of induction heating quenching technology

Induction heating surface quenching technology not only effectively improve the surface properties of metals ( Such as hardness, wear resistance, corrosion resistance, thermal conductivity, electrical conductivity, etc. ) Surface treatment technology, and other commonly used ( Such as carburizing, tempering, surface nitriding, etc. ) Compared with, but also has the following advantages: ( 1) Heating speed, can expand A transition temperature range, shorten the transition time. ( 2) After quenching workpiece surface can get very fine cryptocrystalline martensite, hardness is a little higher, 2～3HRC） 。 Brittle with lower and higher fatigue strength. ( 3) Through the processing of the workpiece is not easy to oxidation decarburization, even some of workpiece processing can be applied directly to use. ( 4) The depth of hardening layer, easy to control the operation, easy to realize mechanization and automation. ( 5) Artifacts can be localized quenching which can accurately using part of the workpiece quenching is required for heating, especially in the magnetizer and use under the condition of high power density. ( 3) Energy saving heat treatment of the energy consumption in comparison with carburizing, nitriding, conditioning has a great advantage, when the workpiece quenching parts quality and the greater the difference between the overall quality, its advantages are more significant. Induction heat treatment often have high added value. ( 4) Rapid induction quenching heat treatment of heating time to trick, generally within 2 ~ 14 s, the production cycle is short, especially under the condition of using the tempering or random induction tempering, the process is similar to machining process. Therefore, modern induction heating quenching equipment has been arranged on the production line or automatic line. ( 5) Clean induction quenching heat treatment quenching liquid is commonly used in water or aqueous solution with additive, quenching, almost no lampblack, good working environment. ( 6) Facilitate mass production mechanization and automation of induction hardening, generally are equipped with progressive beam feeding, artifacts and robot manipulator control sensors, such as reduce the physical labor of the device. Induction heating surface quenching, however, also has its own limits: ( 7) The high cost of tools need to heat treatment furnace is a batch of specialized equipment and tooling that sensors can carry a variety of workpiece heating, carburizing, nitriding, and induction hardening insist on a part of a sensor, and even request a special positioning fixture, etc. , so the high cost of tools. It is only applicable to mass production of one or a race of artifacts. ( 8) Than the high cost of complete sets of equipment investment and general heat treatment equipment, complete sets of equipment including frequency conversion power supplies for inductive heating, quenching machine tool and sensors, as well as the auxiliary cooling water, water quenching liquid circulation device and so on, its relatively high investment cost, maintenance technology and cost is also higher than the general heat treatment equipment [ 2] 。