Titanium is a rare metal with good corrosion resistance and the highest strength to weight ratio in metals. Titanium can also be melted into alloys with other elements such as iron, aluminum, vanadium, and molybdenum to produce high-strength titanium alloys, which are widely used in aerospace, military, industrial automobile, agricultural food, medicine, sporting goods, jewelry, and mobile phones. The smelting methods of titanium and titanium alloys include vacuum consumable furnace (VAR), electron beam cold bed furnace (EB), vacuum plasma arc and vacuum plasma beam smelting (PA), and cold bed furnace smelting (CHM). Among them, the first two are the preferred equipment for smelting titanium and titanium alloy. There are many var furnaces in China, while there are relatively few EB furnaces. The difference between the two is:
1. Principle
1) EB furnace uses the electric field generated by the electron beam gun to accelerate the electron East as the heat source to bombard the molten metal, and convert the kinetic energy of the electron into heat energy, so as to heat the molten metal.
2) VAR furnace uses a consumable electrode rod as a cathode in a vacuum or inert atmosphere, melts rapidly under the high temperature of DC arc, and forms a molten pool in a water-cooled copper crucible.
2. Advantages of EB furnace
1) EB furnace can fully remove high and low-density inclusions and produce high-end products such as aviation titanium alloy. The United States clearly stipulates that aviation titanium alloy must be smelted in an EB furnace
2) EB furnace can produce not only round ingots, but also rectangular ingots for direct rolling, which can save forging and blank opening, so as to greatly reduce metal loss and cost, and produce pure titanium coils and other products at an ultra-low-cost.
3) EB furnace can accept a large amount of residual titanium raw materials. For example, the amount of residual titanium (mass fraction is 62.4 percent ) when American Timet is smelting titanium alloy, can reach 100 percent theoretically.
4) EB furnace can realize one-time melting of most pure titanium and titanium alloy except aviation titanium alloy and other high-end products due to the purification effect of its cold bed refining area, which greatly saves the melting cost.
3. Disadvantages of EB furnace
1) It is difficult to control the composition in the production of titanium alloy. For metals whose vapor pressure is lower than that of pure titanium, such as Al and Cr, the volatilization is large and changes continuously with the operating conditions. For example, the volatilization amount (mass fraction) of Al reaches 1.5 percent . Therefore, a certain degree of operation proficiency and running in the process is required.
2) When titanium alloy is produced, the furnace temperature is high and the vacuum degree is high, and terbium metal volatilization also has a certain loss, usually 2 percent 5 percent .
3) The cost of the EB furnace is high. Compared with the imported var furnace with the same capacity, its cost is 3.5 4 times that of the latter. The investment per ton of material is high, resulting in high equipment depreciation costs. Based on the above characteristics, the EB furnace has been gradually popularized in China in recent years.
VAR titanium ingot normal stock size:
Round shape: 1. OD500x2200mm about 2000kg
2. OD600x2300mm about 3000kg
3. OD950x3000mm about 10000kg
Baoji fairy titanium industry has sophisticated and reliable equipment, mature and advanced technology, qualified and stable product quality, and fully meets the titanium needs of various standards such as ISO (International Organization for Standardization standard), AMS (American aerospace standard), ASTM (American Standard), MIL (American military standard), aviation, aerospace, navigation, medical treatment, chemical industry, metallurgy, power generation and other industries and international markets.
