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

Internal parts of boiler, Internal Parts of boiler: P r essu r e ...

Internal Parts of boiler: P r essu r e Gauge :   For indicating steam pressure W ater Level Indicator : for indicating water level. Steam Stop Valve : Permits fl

Explain the statement- subsidence of the ground, Explain the statement- su...

Explain the statement- subsidence of  the ground Another type of problem is the subsidence of  the ground due to breakdown of weak rocks like  limestone, soluble rocks (gypsum

GOVERNOR, APPLICATION OF GOVERNOR

APPLICATION OF GOVERNOR

Crankcase-basic components of engine , Crankcase: It is connected to eng...

Crankcase: It is connected to engine cylinder. It splits into two parts, named as right crankcase and left crank case. It supports the kick-starter spindle, crankshaft, main shaf

Moment of couple - mechanics, Moment of couple: Sol.: The moment of ...

Moment of couple: Sol.: The moment of couple is the product of the force (that is one of the forces of two equal and opposite parallel forces) and the arm of couple. Math

Find the maximum permissible, A wooden cylinder (specific gravity = 0.6) of...

A wooden cylinder (specific gravity = 0.6) of circular cross - section having length L and diameter D floats in water. Find the maximum permissible (L/D) ratio so that the cylinder

Shielding gas-argon-advantages of argon, Argon Argon is approximatel...

Argon Argon is approximately one and one third times as heavy as air and ten times heavier than helium. Argon, after leaving the torch nozzle, forms a blanket over the weld

Furances, type of furances and disadvantage advantage

type of furances and disadvantage advantage

Co2 welding gun / torch-co2 welding, CO 2 Welding Gun / Torch The torc...

CO 2 Welding Gun / Torch The torch assembly consists of conduits to supply the consumable wire electrode and the shielding gas into the welding gun. The torch assembly may als

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