Spot welding-resistance welding processes, Mechanical Engineering

Assignment Help:

SPOT WELDING

In this type of welding, after proper cleaning of the surfaces, the metals to be welded are kept one above the other and two copper electrodes are kept on both sides of the plates. The weld cycle consists of four periods.

A) Squeeze Time: A pressure is applied to the electrodes and maintained for a particular interval before further operations start and this time is called squeeze time.

B) Weld Time: This is the period during which the weld current is applied. The duration of application of current is always measured in terms of the number of cycles; each cycle corresponds to 20 ms. (1 / line frequency). The pressure is also maintained during this time.

C) Hold Time: After the passage of current is cut off, the pressure has to be maintained for a brief interval of time so that the heated metal solidifies and forms a weld nugget. This period is called hold time.

 D) Off Time: This is the time for which we have to wait at the end of the spot welding before starting any other welding operation on the materials. Usually, resistance welding is carried out at line frequency (50 Hz) but for some applications high frequency (450 KHz) resistance welding is also employed.


Related Discussions:- Spot welding-resistance welding processes

Sketch merchants force diagram, Merchants force diagram. State the assumpti...

Merchants force diagram. State the assumptions made in development of such diagram.

Derive mathematical equation for bernoulls equation, Derive mathmatical equ...

Derive mathmatical equation for Bernoull's equation, what are the application of Bernoull's equation and illustrate any one.

Internal energy - thermodynamics, Internal Energy (U): It is the energ...

Internal Energy (U): It is the energy possessed by the system on account of its configurations, and motion of atoms and molecules. Not like potential energy and kinetic energy

Stiffness properties in composite materials , There are five elastic proper...

There are five elastic properties needed to represent the elastic behaviour of a unidirectional laminate under in-plane loading, but only four of these are independent. The five

Steps of centrifugal filter and screen filter cleaning, Centrifugal Filter ...

Centrifugal Filter and Screen Filter Cleaning :   Oil may contain impurities. Since the oil passes through all the engine parts, the impurities may harm the parts and cause imprope

Plant layouts - layout design principles, Plant layouts shall provide for a...

Plant layouts shall provide for a maximum of safety and exposure protection from the spread of fire, with ease of operation and maintenance consistent with economical design. Requi

Determine strap beam with suitable demonstration, Determine strap beam with...

Determine strap beam with suitable demonstration. Here observe that R e becomes greater than P e by a magnitude of V while R i becomes less than P i by a magnitude equal to

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd