A method of smelting and distributing materials in a vacuum induction furnace using nickel beads as the main raw material

Abstract

The invention relates to a smelting distributing method utilizing nickel beads as a main raw material for a vacuum induction furnace. The smelting distributing method comprises the following steps: (I) cleaning a smelting crucible of the vacuum induction furnace; (II) starting loading after the crucible is inclined by 10-15 degrees; (III) putting partial nickel beads into the bottom of the crucible until the bottom of the crucible is full; (IV) flatly paving 50%+ / -10% of Cr into the crucible; (V) adding the mixture of Ni and residual Cr into the crucible, wherein the area of Cr is 10%-25% of the flat paving area; rotating until the angle of the crucible is vertical to the horizontal direction; adding Ni beads, wherein the amount of the added Ni beads is more than 60% of the total added amount of Ni beads in the smelting process; and adding the residual Ni beads as a feed supplement in batches in the last stage of smelting; (VI)during distributing, tightly distributing materials at the bottom of crucible, and sparsely distributing materials at the middle upper part of the crucible; and (VII) adding easily-burnt elements including Al, Ti, B, Mg and Zr in the last stage of refining and an alloying stage. According to the smelting distributing method, an electric discharge phenomenon which appears on the surfaces of the Ni beads in the presence of induced current during smelting is avoided, and the phenomenon that the adjacent nickel beads are adhered after discharging is avoided.

Description

technical field [0001] The invention belongs to the technical field of vacuum induction smelting, in particular to a material distribution method for vacuum induction furnace smelting with nickel beads as the main raw material. Background technique [0002] Vacuum induction smelting is an important process for the production of superalloys. It has a series of advantages such as strong degassing ability, precise composition control, low inclusion content, and pure steel. For nickel-based alloys with harsh service environments and harsh service conditions, such as: petrochemical, thermal power generation, turbine disks for aircraft, and shafts for aircraft engines, the first manufacturing process must be vacuum induction smelting, and it is required to use pure Metal raw materials. Generally, the Ni content in nickel-based alloys is greater than 50%, and pure metal Ni is mainly divided into nickel plates, nickel beans and nickel beads. Among them, nickel beads are the highes...

AI Technical Summary

Problems solved by technology

However, in the process of vacuum induction smelting, it was found that when nickel beads were used as the main smelting raw materials, the traditional distribution method with nickel plates and nickel beans as the main raw materials continued to be used (the traditional method of distribution was nickel as the bottom, and all Co, Mo, and Nb were added in turn. , W, and the last nickel is covered) it is very easy to cause the top material to stick, and the problem cannot be solved with a ramming rod, so it is forced to break the vacuum treatment

Because the smelted alloy generally contains a large amount of other expensive metals such as Co, Mo, Nb, W, etc., resulting in a large amount of economic losses

The bonding phenomenon of the top material produced by the vacuum induction smelting superalloy with Ni beads as the main raw material will cause the discharge phenomenon on the surface of the metal Ni beads under the action of the induced current, and the adjacent nickel beads will produce a similar "welding" adhesion phenomenon after discharge. When all the nickel beads on the surface of the crucible are "welded" into a whole, it is equivalent to forming a "pot cover" on the upper part of the crucible body, and it is very strong, unable to melt and sink, so that the vacuum induction smelting fails