Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
SHIELDED METAL ARC WELDING (SMAW)
It also known as Manual Metal Arc Welding (MMAW). The heat required for welding is generated by the electric arc formed between metallic electrode and base metal. When the welder touches the plate to be welded with the electrode, immediately a high starting current flows which melts the tip of the electrode, thus initiating the welding arc. If the welder maintains the arc gap, the arc continues to remain stable and the arc heat melts the plate, electrode and the flux coating. The flux covering of the electrode melts in the arc heat and produces a large volume of gases and the slag. The gases cover the arc and shield it from reacting with the atmospheric air. The slag covers the molten metal pool until it solidifies. The slag can be removed after welding. The flux also provides filler metal with alloying elements to increase the strength of the weld joint. The electrode is consumed in the arc during welding. In SMAW, the electrode polarity i s chosen depending on the manufacturers recommendation, which is printed on the cover of the electrode pocket.Shielded metal arc welding is the most common, versatile and least expensive one and accounts for nearly 25 % of total welding in developed countries and nearly 65 % of total welding in India. The electrode diameter varying from 1.6 mm to 6.3 mm and length varying from 250 mm to 450 mm. The power supply required for welding may be either a transformer or motor- generator or transformer - rectifier supplying AC or DC power. For achieving high quality welding, thyristor controlled or transistor controlled or inverter based power sources are employed. These latest solid state type of power sources is having feedback controls to deliver the controlled amount of voltage and current to the welding arc to achieve desired weld quality. The inverter power supplies are the latest technology and upto date power source. The main advantage of this power supply is the portability, lightweight and robust design. It can give required characteristics so that we can do SMAW, GTAW, GMAW, FCAW and gouging with the same power supply.
Displacement or Swept Volume ( V s ) : The nominal volume swept by the working piston when travelling from one dead centre to the other is called the displacement volume. It is e
ABCDEF is a regular hexagon having forces of magnitude 3, 6√3, 12, 3√3 and 6N which act at ‘A' in the direction of AB, AC, AD, AE and AF respectively. Determine the resultant compl
instant center of direct contact slider
Illustrate in brief the types of power plant? Illustrate the factor to be considered for site selection in hydro power plant? a) Compare stream power plant with hydro power p
A heating section consists of a 10 in diameter duct which houses a 8 kW electric resistance heater. Air enters the heating section at 14.7 psia 40oF, and 35 percent relative humidi
what are the tests to carried out after mockup preparation
Compute the angular velocity of the wheel: A wheel of 0.5 m radius rolls over a horizontal surface without slipping as illustrated in Figure (a). The velocity of its centre is
Illustrate about the term bearing capacity? The bearing capacity of a soil mass frequently termed as the ability of the soil to carry the loads without any failure. The foun
What are the Technical Limitations of screw conveyer Technical Limitations: ? Turning limitation of this mechanism Actually the Maximum Turning of U-joint is 18° to 2
Pier and Well Foundations Pier foundations are used when the loads to be transmitted are heavier than loads those can bc acconlplished by piles. They are essentially bearing i
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd