The chemical composition of the medium frequency furnace is unstable, and some chemical elements are easy to overproof, and the content of carbon is relatively high. So it is not suitable for deep processing. Second, because of the material reasons, the tube surface of medium frequency is easy to occur quality problem, such as peeling, pressing points, the light is dark.

Refining furnaces and J3 are mainly of different carbon content, high carbon content, high hardness, brittle, they are not suitable for bending.