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Flame Hardening in Heat Treatment of Metals :

 



The process of hardening steel by heating it with the flame of an oxy-acetylene torch is known as flame hardening which , like the induction - hardening process , is based on rapid heating and quenching of the surface by water. The flame is directed to the desired part without heating the remainder of work efficiently to affect it. The advantages in favor of its application are as follows :

1. Because it heats quickly , flame heating is convenient when hardness is required only for a limited depth, the remainder retaining its original toughness and ductility.

2. Flame heating makes it possible and practical to harden a part or all of a piece of work that is too large or too inconvenient to place in a furnace.

3. The amount of time required for heating is less with flame heating than with a furnace.  

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