How to smelt titanium and titanium alloy in general?
Titanium and titanium alloy melting point is high, chemical properties are active, easy to interact with air and refractory materials in the melting state, usually with water-cooled copper crucible vacuum consumable electric arc furnace smelting, can also be used for plasma furnace smelting, in recent years also developed cold bed furnace smelting, cast into flat ingot. The following mainly introduces the vacuum consumable arc furnace smelting and cold bed furnace smelting.
The smelting process of vacuum consumable
electric arc furnace is briefly described.
Vacuum consumable electric arc furnace
melting, also called VAR (vacume Arc remelting).Sponge titanium and alloy material
according to a certain proportion of chemical composition, mixed evenly after
pressing different shapes of blocks, using vacuum plasma welding box to weld
these blocks into electrodes, in vacuum or situation under the protection of
vacuum or inert gas, it is smelted into an ingot after two measurements.
Special purpose titanium ingots require three
smelting. Industrial-scale titanium ingots are generally 3-6 tons
Cold hearth melting technology, also known as CHM (Cold hearth Melting), includes electron beam cold hearth melting (EBCHM) and plasma cold hearth melting (PACHM),Main equipment consists of electron gun or plasma gun (EB PA), cold hearth (CH) and crystallizer (CR). It has three working areas, namely melting area, refining area and crystallization area. Cold bed furnace is a more complex vacuum melting equipment, it is composed of furnace chamber, gun, vacuum system, power supply system, cooling system, feeding mechanism, crucible and drawing mechanism 7 parts. Figure 7-3 shows the general situation of EBCHR cold bed furnace.
Volatile impurities can be effectively removed under vacuum for a long time, while high-density impurities (such as WC) can melt or sink and bond to the bottom of the shell. By controlling the superheat of the melt at the outlet of the crystallizer is very small and the melt pool is shallow, which is conducive to obtaining homogeneous fine grain ingot. The technology can also recover large amounts of titanium debris, thus reducing costs.