VAR furnace, also known as vacuum consumable electrode arc melting furnace, is a process in which the consumable electrode is heated and melted by a controllable AC arc in a vacuum environment to remelt the metal ingots.
Vacuum consumable arc melting technology is widely used in the production of high-quality high-temperature alloys and aviation titanium alloy ingots. It is a mature industrial melting method. It is characterized by fast melting speed and can produce large ingots. The ingots produced can basically meet the requirements of general industry. The purpose of remelting is to produce dense, defect-free, uniform ingots with the required chemical composition, size and grain structure.
The VAR furnace consists of a vacuum system, an electrode drive mechanical system, a copper crucible and a cooling circulation system, a DC power supply, an automatic and manual control system, an arc stabilization stirring system, a monitoring and automatic recording system, etc. During smelting, the electrode is melted under vacuum using the high temperature generated by the arc discharge between the electrode and the crucible as a heat source. The electrode is made of the smelted metal material. During smelting, the consumable electrode is continuously melted, and at the same time, the ingot is continuously solidified and increased in the crystallizer from bottom to top. The basic process of the VAR smelting process is: mixing → pressing the electrode → welding the electrode and the residual material into a consumable electrode → smelting → ingot processing → inspection. Since the crucible diameter is generally 0.050~0.150 m larger than the electrode, the electrode must move downward at a certain speed to keep the distance between the electrode end and the molten pool constant. The cooling water takes away the heat from the crucible wall, causing the molten metal to solidify on the crucible wall. For nickel-based high-temperature alloys that are prone to segregation, the melting rate is relatively low (3~4 kg/min), which can form a stable solidification pattern, that is, a basin-shaped molten pool and a solidified ingot under the molten pool. VAR furnaces are now in a relatively complete stage, with the characteristics of coaxiality, reproducibility and flexibility in structure, and are developing towards larger capacity and long-distance precision operation. VAR furnaces use advanced computer automatic electronic control and data collection systems, which can establish a good melting pattern for given alloys and ingot specifications.
VAR melting technology has the following characteristics:
① Remove gases such as hydrogen;
② Reduce the content of high vapor pressure trace elements;
③ Obtain near-directional solidified columnar crystals from bottom to top, thereby reducing macro-segregation and micro-segregation.
Can Be Customized from 100Kg to 10000Kg
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