2. Introduction
Spot welding is the process in which the adjoining metal
surfaces are joint together by the heat obtained from resistant
to current flow, thus forming welding Nugget between them.
3. Working Principle:
At Low voltage, high current flowing through the joint generates large amount
of heat due to High Contact Resistance, which causes Melting of Joint and
further Fusion of Metals.
Mathematically, the heat generated is given by the formula:
H = I2Rt
4. How Does it Work?
Let us consider two plates and try to join them
9. 5. Pressure Off step
Removal of the electrodes from the join area and further the joint is allowed
to cool.
So the technique in which metals are joint with each
other by resistance heating at a single point is called
Resistance spot welding
11. Advantages:
Limitations:
Quick and Easy
No need of Flux and Filler metals
Multiple sheets joined together at the same time
No dangerous open flames
Saves production cost
Difficulty for maintenance or repair
Generally have higher cost than most arc welding equipment
Low tensile and fatigue strength
The full strength of the sheet cannot prevail across a spot welded joint
