Explain the principal of resistance welding and its advantages
Answers
Answer:
Resistance welding is used for joining two metals.
It consists of a welding head, which holds the metal between its electrodes and applies pressure, and a welding power supply, which applies electric current to the metal to be welded.
Resistance generates friction heat when force is applied. Resistance welding utilizes this heat.
Similarly, when an electric current tries to move forward through two metals, heat is generated due to the resistance of the metal itself and the friction at the contact point.
Resistance welding welds a metal to another metal utilizing this heat and pressure.
Answer:
Principle:
All resistance welding like spot welding, seam welding, projection welding etc. are worked on same principle of heat generation due to electric resistance. When a current passes through electric resistance, it produces heat. This is same principle which is used in electric coil. The amount of heat produced is depends on resistance of material, surface conditions, current supplied, time duration of current supplied etc. This heat generation takes place due to conversion of electric energy into thermal energy. The heat generation formula is
H = I2RT
Where
H = Heat generated in joule
I = Electric current in ampere
R = Electric resistance in Ohm
T = Time of current flow in second
This heat is used to melt the interface metal to form a strong weld joint by fusion. This process produces weld without application of any filler material, flux and shielding gases.
Explanation:
Advantages:
It can weld thin (0.1 mm) as well as thick (20mm) metals.
High welding speed.
Easily automated.
Both similar and dissimilar metals can be weld.
The process is simple and fully automated so does not required high skilled labor.
High production rate.
It is environment friendly process.
It does not require any filler metal, flux and shielding gases.