Electro-slag remelting and vacuum induction melting

Electroslag remelting (ESR),also known as electroslag remelting,is a process for remelting and refining steel and other alloys used in mission-critical applications in aircraft,thermal and nuclear power plants,military technology and other fields.The electroslag remelting (ESR) process is used to remelt and refine steel and various superalloys to produce high-quality ingots.The process can be initiated by vacuum induction melting.The ESR process uses as-cast alloys as consumable electrodes.An electric current (usually alternating current) is passed between the electrodes and a new ingot,which is formed at the bottom of a water-cooled copper mold.The new ingot is covered with engineering slag superheated by an electric current.The electrode tip slowly melts from contact with the slag.These metal droplets travel through the slag to the bottom of the water-cooled mold,where they slowly freeze as the ingot solidifies directed upward from the bottom of the mold.The slag pool floats above the refined alloy,floating upward as the alloy solidifies.Removes impurities from the molten metal that would chemically react with the slag or otherwise float to the top of the molten pool as the droplets pass through the slag.Electroslag remelting uses highly reactive slag (calcium fluoride,lime,alumina or other oxides are often the main constituents) to reduce the amount of Type A sulfide present in biometal alloys.This is a common practice in European industry.ESR can also reduce other types of inclusions and is considered an alternative to the vacuum arc remelting (VAR) method commonly used in the US industry.An example of the use of electroslag refined (ESR) steel technology is the L30 tank gun.CrNi60WTi is a stainless steel that is best formed by electroslag remelting or vacuum arc remelting.This alloy can be used in the construction of nuclear power plants. 

1.An electroslag remelting furnace for consumable electrodes comprising a mold for receiving a melt formed from electrode material;at least one drive motor and at least one mandrel and associated mandrel nut for the electrode Vertical movement;at least one guide column,which is arranged for vertically guiding the consumable electrode and extends parallel to the main shaft and the two ends of the main shaft are rotatably mounted relative to the guide post;at least one clamping for the consumable electrode.A device comprising a spindle nut fixed in position,a spindle mounted in the spindle nut and movable vertically therein,the spindle being connected by its lower end to the clamping device,and a guide on which the guide column together with the spindle is movably mounted middle.

2.The electroslag remelting furnace according to claim 1,characterized in that a driving motor is connected to the main shaft.

3.The electroslag remelting furnace according to claim 1,characterized in that the spindle nut is rotatably mounted and has a drive motor associated therewith.

4.The electroslag remelting furnace of claim 1,wherein a separate drive motor is associated with the spindle and the spindle nut.

5.The electroslag remelting furnace according to claim 1,characterized in that the guide device is fixedly arranged on the furnace frame.

6.The electroslag remelting furnace according to claim 1,characterized in that one or more guide posts are also designed as power supply elements.

7 .The electroslag remelting furnace according to claim 6,wherein scrapers with fixed positions are arranged on the guide posts respectively.

8.The electroslag remelting furnace according to any one of the preceding claims,characterized in that an additional lifting drive is arranged between the main shaft and the guide column,by means of which a limited movement relative to the main shaft is superimposed on the guide post.

9.The electroslag remelting furnace according to claim 8,wherein the clamping device has two relatively movable clamping parts,one of which is connected to the main shaft and the other is connected to the column.

10.The electroslag remelting furnace according to claim 1,characterized in that,the lower end of the guide post is located above the upper edge of the casting mold at the bottom position.

Vacuum induction melting

Vacuum induction melting (VIM) uses an electric current to melt metal in a vacuum.The first prototype was developed in 1920.Induction heating induces eddy currents in the conductor.The eddy currents create a thermal effect to melt the metal. Vacuum induction melting has been used in the aerospace and nuclear industries.

Program

VIM involves placing a coreless induction furnace in a vacuum chamber.Melting and casting operations are performed at low pressures to control the overall alloy chemistry.

Uses

VIM is particularly useful in the production of alloys with melting points in excess of those practical for other smelts.Nickel,nickel-iron and superalloys are often produced using this process.The VIM process is typically used for small batch production and allows a high degree of control over the alloy composition. Environmental contamination (dust, etc.) and oxidation are low,while normally unwanted elements such as hydrogen or nitrogen can be removed from the process.