Reducing flame is obtained in oxyactetylane welding with
-
excess oxygen
-
equal parts of both gases
-
excess of acetylene
-
reduced acetylene
A reducing flame (also called carburizing flame) in oxyacetylene welding is obtained with excess acetylene. This flame has an inner cone, a feathered intermediate zone, and an outer flame, characterized by a deficiency of oxygen which prevents the burning of all available acetylene, creating a reducing atmosphere that prevents oxidation.
To answer this question, you need to understand the concept of oxyacetylene welding and the properties of the reducing flame.
Oxyacetylene welding is a process that uses a mixture of oxygen and acetylene gases to create a high-temperature flame for melting and joining metal parts. The flame used in oxyacetylene welding can have different properties, depending on the ratio of oxygen to acetylene in the mixture.
There are two types of flames commonly used in oxyacetylene welding: the oxidizing flame and the reducing flame. The oxidizing flame has an excess of oxygen compared to acetylene, while the reducing flame has an excess of acetylene compared to oxygen.
The reducing flame is obtained in oxyacetylene welding with an excess of acetylene. This means that there is a higher concentration of acetylene in the mixture compared to oxygen. The excess acetylene creates a fuel-rich environment, resulting in a flame with a reducing atmosphere.
In a reducing flame, the excess acetylene acts as a reducing agent, removing oxygen from the metal being welded. This helps prevent oxidation and ensures a clean weld with good metallurgical properties.
Therefore, the correct answer is C. Excess of acetylene is required to obtain a reducing flame in oxyacetylene welding.