This set of Welding Multiple Choice Questions & Answers focuses on “Thermit Welding”.
1. In an iron thermit, how many moles of aluminium reacts with three moles of iron oxide to give nine moles of iron?
Explanation: The thermit process, which is used for welding depends on the chemical reaction between oxide of iron and aluminium metal. According to this reaction, when 8 moles of aluminium reacts with 3 moles of iron oxide, then, 4 moles of aluminium oxide and 9 moles of iron is formed.
Explanation: Around the parts which are to be united, superheated liquid steel is poured, which then effects in forming the weld. This process, hence, is a fusion welding process. The part represented by the question mark is the crucible.
Explanation: In this apparatus of the thermit welding process, the question mark here represents the pattern made up of wax. This process is basically carried out in fusion welding.
Explanation: In this figure, the question mark is represented by the runner. This process is carried out at fusion welding.
Explanation: The part represented by the question mark is the sand plug. Superheated liquid steel is poured, which then effects in forming the weld. This process, hence, is a fusion welding process.
8. After the achievement of welding temperature, electrical connections are established to complete the weld.
Explanation: The superheated melt is heated from the crucible gets poured around the metal parts. As the welding temperature is achieved, there is an application of mechanical pressure to the weld.
9. What is the magnitude of temperature produced in a thermit reaction?
Explanation: Thermit welding is called as fusion welding. A superheated melt operates in this type of melt. The heat that is produced has the temperature approximately twice than that of the melting point of steel, which is about 3000°C.
10. Thermit welding is used for making rail tracks.
Explanation: A superheated melt operates in this type of melt. The production of pipes, rail tracks, shafts or big gears can be done using thermit pressure welding. Thermit welding is called as fusion welding.
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