Process analysis of rods using ultrasonic induction heating equipment for induction heating normalizing and rapid spheroidizing annealing

In order to meet the needs of bar work, the bar needs to use ultrasonic induction heating equipment for induction heating normalizing and rapid spheroidizing annealing. Today, the editor will tell you about the heat treatment process of bar induction heating normalizing and rapid spheroidizing annealing.

Use ultrasonic induction heating equipment to heat the steel to 100-150°C above Ac1, then air-cool to about 20°C below A1 to obtain a pearlite structure, and then heat to 700-720°C for spheroidization annealing.

Tests were conducted on three types of carbon tool steel wires, T7, T10, and T12, with a diameter of 2.2 mm, using the normalizing rapid spheroidizing annealing process. The heating rate of the steel wire is 20°C.S-1. After heating to the austenitizing temperature, it is then cooled to the spheroidizing temperature at a cooling rate of 100°C.min-l and held for spheroidizing annealing. The specific annealing process parameters are listed in the table below.

Tl0 steel obtains a granular pearlite structure after isothermal treatment at 700°C for 180 minutes. After 60 minutes of heat preservation, the carbide begins to spheroidize. When the heat preservation time reaches 3 hours, the ideal spheroidized structure can be obtained. Compared with the traditional heating spheroidizing annealing process, the spheroidizing speed is significantly accelerated. After comparison, it can be seen that only the holding time, the rapid spheroidizing annealing process is shortened from 8h to 2h.

This article briefly introduces the heat treatment process of bar induction heating normalizing and rapid spheroidizing annealing. Many manufacturers use the above process for heat treatment, and the workpieces produced are of good quality and meet the work needs.