Preventive measures and maintenance of ultrasonic quenching machine and high-frequency furnace quenching longitudinal crack prevention

① Use slow cooling medium, such as oil. Water and oil double-liquid quenching can also be used, but water and oil double-liquid quenching has no practical value for some small parts.

② The workpiece should be heated to avoid overheating. It can be properly pre-cooled after being released from the furnace, and tempered in time after quenching.

③ Strengthen technical management and technical training, and practically educate relevant process operators on the theory of quenching and cracking.