Process overview of bending pipes heat treatment by medium frequency induction heating power supply

Elbows are an important part of oil and gas transmission pipelines and must withstand huge friction during work. For this reason, we often use medium frequency induction heating power to conduct induction heating heat treatment on elbows, and the effect is very good. Today, the editor will give you an overview of the induction heating process of bent pipes.

The schematic diagram of the induction heating elbow is shown in Figure 10-1. When bending the pipe, the induction coil is placed at a specific part of the steel pipe. One end of the steel pipe is placed on a connector supported by a positioning guide roller, and the other end is fixed by a rotatable crank arm chuck. When the induction coil is fed with a medium-frequency current, the local steel pipe is quickly heated to a predetermined temperature. At the same time, under the action of the extrusion force, the steel pipe begins to thermally deform along a predetermined arc. The deformed elbow is quenched and cooled, and the quenching medium usually uses water spray cooling or cold air cooling. The thermal deformation speed is slow, and the induction coil maintains a stable heating temperature, so that the bending and quenching processes proceed sequentially.

It can be seen from the hot bending deformation process of steel pipes that the outer arc of the steel pipe is affected by tensile stress and the pipe wall becomes thinner, and the inner arc is affected by compressive stress and the pipe wall thickens. The side deformation of the steel pipe is different from the outer arc and the inner arc. The entire bent pipe section is subject to a variety of complex stresses, which will also have significant differences in the mechanical properties of different parts of the steel pipe after heat treatment.

This article briefly introduces the induction heating process of bent pipes. I hope it can be helpful to your heat treatment work. If you want to know the specific process information of elbow induction heating, you can consult our technical staff.