Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding
â?‘ Resistive Spot Welding is a process in which contacting metal surfaces are joined by the heat obtained from resistance to electric current
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding
Spot Welding
• Welding cycle: ⮚ Electrodes contact the metal (pressure is applied) Known as squeeze time ⮚ Current is passed between electrodes the temperature increases at the contact point the metals melt- the electrodes squeeze the material• Weld time: ⮚ Current is shut –down pressure increased- hold time pressure is released- off time weld nugget is formed
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding
Parts Of The Machine
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding
Working Principle
H = I2RT I – Current R – Resistance of the conductor T – Time of current flow
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding ADVANTAGES
❖ 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 ❖ Dimensional Accuracy
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding
LIMITATIONS
• 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
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding APPLICATIONS
Automobile industry
Dental Prosthesis
Batteries
Nuts and Bolts
Chapter Name :- Welding Process Topic Name
:- Resistance Welding - Spot Welding
Spot welding in Aircraft