Steel parts are quenched and tempered using a medium frequency induction heating machine. What are the contents of quality control?

After the workpiece is induction hardened, some residual stress will be generated. At this time, we need to temper the workpiece. The purpose of tempering is to eliminate stress and stabilize the size of the workpiece. The quenching and tempering of steel parts are commonly performed with medium frequency induction heating machines. What are the quality controls during the quenching and tempering process? Today, the editor will tell you the answer.

(1) Design and selection of sensors

The structure, shape and dimensional accuracy of the inductor and sprinkler of the medium frequency induction heating machine should meet the usage requirements.

(2) Inspection of sensors

Check the cooler and related fixtures to confirm the deformation, damage and coil status of the sensor; also check and clean the water outlet of the cooler, and confirm that the fixture can operate normally. Good contact must be maintained between the inductor and the transformer end plates.

(3) Clamping of workpieces

When clamping, the relative position of the workpiece and the sensor must be strictly maintained. In particular, attention should be paid to eccentricity and tilt to ensure that the heating and cooling rates are relatively uniform. Avoid contact discharge and other faults between the sensor and the workpiece due to expansion and distortion caused by local heating of the workpiece.

(4) Quenching, heating and cooling of the workpiece

According to the workpiece, equipment conditions and test results, determine the heating process parameters, such as power or loop voltage, heating temperature, heating time or workpiece feed speed, etc.

Select an appropriate cooling medium and test to determine the cooling process parameters, such as medium temperature, pressure, flow rate, concentration range and cooling time. Pressure quenching can also be used to control workpiece distortion when necessary.

(5) Tempering heating and cooling of the workpiece

When tempering, heating and cooling, confirm the heating and cooling conditions. In order to avoid cracking, distortion and other defects, tempering should be carried out in time after quenching. Self-tempering method can also be used. The tempering temperature should be selected so that the workpiece and surface obtain the specified properties.

(6) Straightening treatment after induction hardening and tempering

After heat treatment, the workpiece that needs to be straightened should be ensured that the residual stress generated by the straightening does not hinder subsequent machining and use, and stress relief treatment should be performed when necessary.

(7)Record

The treatment process should be recorded in accordance with regulations and process requirements, and properly kept for future reference.

As a leader in the induction heating industry, Zhengzhou Gou's is quite familiar with the manufacturing of medium frequency induction heating machines and medium frequency induction heating furnaces, and also has a good understanding of their heat treatment processes. Today, the editor only introduces some of them, hoping to help everyone. For more details please call us