Common defects and countermeasures of crankshaft induction hardening

Crankshaft induction quenching is an important process in the heat treatment process and is a necessary measure for hardening the crankshaft diameter. However, there will always be some problems during the quenching process. What should we do? Take a look at the introduction below.

Common defects of crankshaft induction quenching: uneven distribution of hardened layer and its countermeasures

(1) The shaft diameter is not concentric with the sensor. To address this problem, we should adjust the positioning device to prevent the parts from deviating to ensure that the heating requirements are met.

(2) The current distribution in the inductor is uneven. We can configure a magnetic conductor to solve this small problem.

(3) There are oil holes, just plug them.

(4) The water spray holes of the sensor are uneven. At this time, we should arrange the position of the water spray holes reasonably.

Common defects of crankshaft induction hardening, occurrence and countermeasures of radial cracks in oil holes

(1) The oil holes are heated unevenly or are locally overheated, the grains are coarse, and the oil holes have poor finish. We need to block the oil holes or configure magnets to reduce the surface roughness of the oil holes to meet the processing requirements.

(2) If cooling is uneven or too intense, we can use half-circle inductor heating and water immersion cooling to improve cooling conditions.

Common defects of crankshaft induction hardening, manifestations of C-shaped cracks and surface spalling and countermeasures.

(1) Forging and folding, we should reasonably improve the forging process.

(2) The quenching cracks in the oil holes expand. We should improve the design of the oil holes to meet the requirements.

(3) The hardened layer is too deep or uneven, which is mainly due to blocked oil holes.

(4) The surface cooling is not good during grinding. We should improve the grinding process of the crankshaft.

(5) The tempering temperature is low. This is simple. Just find a way to increase the tempering temperature to meet the process requirements.

Common induction quenching defects of crankshafts, manifestations of cracks in the quenching transition zone and how to solve them.

(1) The quenching stress is too large. At this time, we should check the machine to ensure that the sensor is concentric with the shaft diameter.

(2) Improper grinding cooling, we should improve the grinding process (control grinding allowance, grinding conditions and improve cooling methods, etc.).

(3) The normalizing temperature is too high, and the secondary generation of austenite reduces the toughness of the material. At this time, we need to reasonably select the heat treatment process parameters.

Common induction hardening defects of crankshafts, insufficient hardness, soft spots and soft bands and how to solve them  

(1) The material has low carbon content or has a banded structure. We should check the chemical composition to ensure that the structure is qualified.

(2) The quenching temperature is low, and the heating time is used to increase the quenching temperature.

(3) The cooling water pressure is low or the water temperature is high. Increase the cooling water pressure or lower the water temperature appropriately.

(4) The water spray hole of the sensor is partially blocked. We should clean the water spray hole on the sensor to ensure that it is not blocked.

After reading, if you still have questions in this regard, you can call us for consultation. Zhengzhou Gou's is a manufacturer specializing in the production of high-frequency induction heating equipment, medium-frequency melting furnaces, and over-frequency induction heating equipment. It has many years of experience in induction heating.