WELDING PROCESS

1. OXY ACETYLENE WELDING
BY
ARAVINDKUMAR B

2. GAS WELDING
 performed by burning a combustible gas with air or
oxygen: results in a concentrated flame of high
temperature
 purpose of flame is to heat and melt the parent
metal and filler rod.

3. OXY ACETYLENE WELDING
 Done by melting the edges or surfaces to be joined
by gas flame and allowing the molten metal to flow
together to form a solid continuous joint.
 Suitable for joining the metal sheets and plates
having thickness of 2-50 mm.
 filler metal is added in the form of welding rod for
material >16mm thickness.
 Oxygen –acetylene mixture is used to a greater
extent than the other combination
 The temperature produced by the oxy–acetylene
flame 3200ºC (sufficient to melt the 50mm thick
plate)

5. GAS FLAME
 correct adjustment of flame is important for reliable
work.
 when oxygen and acetylene are supplied in nearly
equal volumes a neutral flame is produced having a
maximum temperature of 3200ºC
 condition of flame is determined by its appearance.
 neutral flame is desired for most welding operation.
 When excess of oxygen is used –oxidizing flame.
 When excess of acetylene is used –carburizing
flame.

6. NEUTRAL FLAME
 Neutral flame has two definite zones
 sharp brilliant cone extending a short distance from
the tip of torch
 Outer envelope –bluish in colour.
 inner cone develops heat and the outer envelope
protects the molten metal from oxidation
 neutral flame is used for welding steel, SS, C.I, Cu,
AL, etc.

7. CARBURIZING FLAME.
 Percentage of acetylene is more and 3 zones
 sharply defined inner cone
 intermediate cone of whitish colour (feather)
 bluish outer cone
 the length of intermediate cone is an indication of
proportion of excess acetylene in flame.
 While welding steel ,the presence of more acetylene tend
to give the weld a higher carbon content then parent
 metal ,resulting in a hard and brittle weld.

8. OXIDIZING FLAME
 percentage of oxygen is more
 have two zones
 small inner cone which has purple colour
 outer cone/envelope
 this flame is used for welding brass metal