What defects will occur when spring steel plates are heat treated with ultrasonic induction heating equipment?

When the workpiece is heat treated, it is affected by some factors and will produce some defects. Therefore, it is important to understand the causes of defects and understand how to prevent them. What defects will occur when spring steel plates are heat treated with ultrasonic induction heating equipment? What are the causes and remedies? If you want to know, just read the article below.

1. Surface corrosion occurs because the surface of the parts is not clean. We can use shot blasting or sand blasting to remove dirt, oil or other dirt on the surface so as not to affect surface cleanliness.

2. Causes and remedial measures for surface oxidation, decarburization or elemental depletion:

(1) The heating and holding time is long, we must shorten the heating time.

(2) The raw materials themselves are decarbonized, and we should strictly inspect the raw materials.

(3) The furnace temperature is too high. Control the furnace temperature within the process range.

(4) The salt bath deoxidation is not sufficient during quenching and heating. We should fully deoxidize.

3. Insufficient hardness and low elasticity. Insufficient hardness of the workpiece during heat treatment is a relatively harmful defect. The causes and measures are as follows:

(1) If the heating temperature is high or low, strictly follow the process regulations to avoid the temperature being too high or too low.

(2) The austenite grains become coarse during heating, and we should strictly control the temperature and holding time.

(3) The tempering process is improper and the process parameters must be reasonably formulated.

(4) The surface is decarburized during quenching and heating to increase the tempering temperature.

(5) Insufficient or uneven cooling, we should strengthen the circulation of the cooling system to ensure uniform cooling.

4. Brittleness, causes of brittleness:

(1) If there is overheating, we should strictly control the heating temperature and holding time. Overheated springs can be reheated after normalizing.

(2) Cooling is slow, resulting in temper brittleness, and rapid cooling after tempering heating.

5. Tissue overheating or overheating, causes and remedial measures:

(1) The heating temperature is too high. We should correct the temperature in time and strengthen metallographic inspection.

(2) The heat preservation time is too long, choose a reasonable heat preservation time.

6. Quenching cracking, this is a common defect in the heat treatment of workpieces. Its causes and how to prevent it:

(1) The cooling speed is fast and the quenching medium is improperly selected. We must choose a cooling medium that meets the requirements to ensure the cooling effect.

(2) The quenching heating speed is fast and there is no preheating or insufficient preheating. We should fully preheat or stage heating.

(3) The heating temperature is too high or the holding time is too long, so we should strictly implement the heating temperature and holding time specified in the process.

7. Unqualified deformation, causes and remedial measures for this defect:

(1) The tempering pressing force is insufficient. We need to check whether the tempering tire meets the technical requirements and the preloading force must be reasonable.

(2) Uneven cooling increases the speed of oil circulation and does not allow the oil temperature to rise suddenly.

(3) There is too much retained austenite. We need to use ice treatment to reduce the amount of retained austenite.

(4) Improper placement during heating. We need to ensure that there is no overlap between steel plates.

Regarding the defects caused by spring steel plates during heat treatment using ultrasonic induction heating equipment, today I will tell you these tips. If you want to know more remedial measures, please call us for consultation.