Tungsten Round Bar
Tungsten is a chemical element with symbol W and atomic number 74. Tungsten word comes from the Swedish name tungstate mineral which means heavy stone.
Tungsten alloys:
It can be combined with other metals to increase the strength and resistance to wear and corrosion. Steel alloys often contains tungsten.
Types Of Tungsten Electrodes
- Rare-earth, grey – it comes with the hybrid combinations of oxides. The benefit of this is that the welder can have them in small diameters and can provide good services.
- Pure, green – pure tungsten electrodes are 99.5% tungsten. It is suitable for application of low to medium amperages with magnesium and aluminium alloys.
- Lanthanide, gold – it is suitable to use in direct current. They contain 97.8% tungsten and between 1.3 and 1.7% lanthanum.
- Ceriated, orange – it is ideal for welding small and delicate parts like in thin sheet metal work, pipe fabrication and orbital tube manufacturing. It also includes non-corroding steels, carbon, nickel, aluminium, magnesium, titanium and copper alloys.
- Thoriated, red – it contains 97.3% pure tungsten and 1.7-2.2% thorium oxide, which has low radioactivity. The electrodes are easy to use and lasts for a longer time. They are ideal for welding thin steel because they maintain sharpened edges during manufacturing.
- Zirconiated, brown – it consists of 99.1% pure tungsten and 0.15-0.4 zirconium. These electrodes does not contaminate easily and highly resistant to splitting.
Identification Of Tungsten Ore
- Examine the mineral. It is opaque and slightly metallic. It can be tan to dark brown, golden to pale yellow, brownish yellow, reddish yellow, greenish, colourless or white.
- Rub the mineral against a streak plate, a piece if plain white unglazed porcelain.
- Scratch the mineral with the steel nail, which has hardness of about 5.
- Measure the crystals specific gravity – its weight in comparison with its volume. The measurement can be taken in different ways but it needs a special equipment.
- Drip a small amount of diluted hydrochloric acid on the specimen.