Induction coil is made by step winding method, which is our company patent technology, the invention patent name is: high power coreless induction melting furnace coil winding method (patent number: 201410229369. X). The induction coil copper pipe adopts the high purity oxygen free copper produced by Chinalco copper, and the copper pipe butt is welded by silver base solder. The advanced winding method combined with high conductivity copper pipe and silver welding treatment at the docking place greatly ensures the high energy saving of the induction coil. This induction coil after sandblasting passivation and a series of processing, with German import high temperature insulating paint spraying three times, completely solve the problem of arc striking between traditional induction coil. We adopte advanced process to deal with between water cooling ring and effective coil in induction coil, and solve the arc striking problem between water cooling ring and effective coil in traditional induction coil proeffectively Yoke is made of high permeability cold-rolled silicon steel sheet. Silicon steel sheet thickness is 0.3 mm. The magnetic flux density design under 6000 gauss. Yoke is clamped and supported by both sides of the 304 stainless steel plate and 304 stainless steel clamp, and rod fixed. Stainless steel plate design effectively increase the sink of oral yoke overheating, the sink tube can withstand a hydraulic pressure of 0.8 MPa, no leak within 15 min. Yoke assembly after bending is not greater than 4 mm, the center line of the theory and the actual center line deviation is not more than 3 mm.