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

Scope of strength of materials, Scope of strength of materials: What ...

Scope of strength of materials: What is the scope of strength of materials? Sol.: Strength of materials is science that deals with the relations between externally appl

Design of a filament winding machine, How can I achieve a back and forth mo...

How can I achieve a back and forth movement of carriage system. How can I reverse the motor to go back and forth.

Find out force on each member - truss, Find out force on each member - Trus...

Find out force on each member - Truss: A truss is as shown in the figure given below. Find out force on each member and the nature of it.  Sol.: First we calculate sup

What are the several factors affecting tool life, (a) Draw a single point c...

(a) Draw a single point cutting tool and label clearly the several parts of it. Illustrate them in brief. (b) What are the several factors affecting tool life ? (c) List char

How to select the project if not yet done - general phase, To select the pr...

To select the project, if not already done - Radial Drilling Machine Due to above Problem?s in RADIALL DRILLING machine, now the select the project and solves the problems and

Explain macroscopic approach - thermodynamics, Explain Macroscopic Approach...

Explain Macroscopic Approach - Thermodynamics 1. In this method a fixed quantity of matter is considered without taking into account the events taking place at molecular level.

Remove clutch cover and check clutch- clutch complaint, Remove clutch cover...

Remove clutch cover and check clutch operating arm, spring and clutch lifter rod :Check for free movement of rod clutch lifter in the cover right crankcase. Check for lever comple

Classification of system - thermodynamics, Classification of system - Therm...

Classification of system - Thermodynamics: (1) Kitchen refrigerator, (2) Ceiling fan (3) Thermometer in mouth (4) Air compressor (5) Pressure Cooker (6) Carburetor (7) R

Explain the scope of thermodynamics in thermal engineering, State the scope...

State the scope of thermodynamics in thermal engineering. Thermal engineering is a very significant associate branch of mechanical, chemical, environmental, aerospace, marine,

Calculate machining time and material removal rate, Calculate Machining Tim...

Calculate Machining Time and Material Removal Rate A hole of 40 mm diameter and 50 mm depth is to be drilled in a mild steel component. The cutting speed can be taken as 65 m/

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