In addition to surface hardening, what other applications do induction heating furnaces have?

In addition to surface hardening, induction heating furnaces are also used in the following aspects:

(1) Stress relief and normalizing Figure 3-24 shows a flexible water-cooled coil that wraps the butt weld of a casing, and performs stress relief or annealing on the welding position. Figure 3-25 shows a linear inductor equipped with silicon steel sheets for annealing the longitudinal continuous welds of butt-welded pipes. The linear inductor heats the weld to above the temperature, so that the structure is recrystallized. Both ends of the tractor’s high-pressure tubing are flared (20 steel), and induction normalizing is also used to restore the grains at the head of the shovel to normal.

(2) Pipes for penetration quenching and tempering oil well engineering, the outer diameter is between Φ60~Φ410, the wall thickness is between 5~16mm, and the 1000Hz intermediate frequency power supply has been used for penetration heating quenching and tempering (600 ~ 700 ℃) It is also carried out with an intermediate frequency power supply. The hardening and tempering of screw blanks has also been successfully used in diathermy furnaces.

(3) Induction heating is used to draw the tube. The diameter of the cold drawn tube is reduced in the cold state, and the reduction is small each time, in addition to annealing and pickling, the process is complicated. The use of induction heating to draw the tube can increase the diameter reduction by 1.5 times, and eliminate the annealing, pickling and other processes.