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.
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.