MACHINE FORGING PROCESS

 Machine forging -: This is also known as up-set forging. Both drop and press forging are also done by machines only up-set forging is reffered as machine forging. Up-set machines are generally horizontal acting. The die-set consist of a die and a corresponding punch. The die consist of two parts one called the stationary greeper die which is fixed to the machine frame and other part is moveable greeper die which moves along with the die slide of the up-setter. The stock help between two greeper die by frition. 

                The two dies when in close position forward the necessary die cavity then the having tool advances against the stock and up-set it to completely fill the die cavity. Having completed the upsetting the heading tools moves back to it's back position. Then the moveable greeper die release the stock by sliding member.

Advantages of machine forging -:

1. High production rate up to 4500 parts per hour.

2. The process can be fully automated.

3. Elimination of the forging draft and flash.

4. High efficiency of material utilization, as the process involves little or no waste

METAL INERT GAS WELDING

METAL INERT GAS WELDING -: Metal inert gas welding is also known as " gas metal arc welding " . In this welding utilies a comsumerabl electrod enhance the term metal appear in the title.  There are other gas shielded arc welding process utilising comsumerabl electrods such as flux coat arc welding or of which can be termed under metal inert gas welding. When thicker sheets are to be welded the filler metal requirement the gas metal welding. 

                   

 

 The tipical set-up for MIG show in fig. The comsumerabl electrod is the form of a wire rill,  which is fed at a constant rate . The welding torch is connected to the gas supply cylinder which provide the necessary inert gas . The electrod and workpiece are connected to the welding power supply. The current from the welding machine is change by the rate of feeding of the electrod wire. Normally D.C. arc welding machine are used for metal inert gas welding with electrod positive.

              The shielding gases that can be used for metal inert gas welding are helium, argen , nitrogen, oxygen and carbon dioxide and mixture of the above gases in various propositions. Each of this have that the fact on the formation of heat. The electrod wire comes generally in the form of coils . Various wire composition are available depending on the base metal composition.  The diameter of wire may be of order of 0.5 to 3.2 mm. 

SUBMERGED ARC WELDING

SUBMERGED ARC WELDING-: It is generally used for faster doing welding jobs. It is possible to use larger welding electrod 12 mm as well as very high current 4000 ampier so that very high metal disposition rate of the order of 20 kg/hr or more can be achive with process also very high welding speeds 5 meter/minute are possible in submerged arc welding. Some saw machine are able to well plated of thickness as high as 75 mm in butt joints in a single pass .

                 

 The arc is produced by the comsumerable electrod wire is continuously fed into the wild zone. The welding zone is completely covered by a measure amount of granulated flux which is delivert at a rate of the welding electrod by means suffer welding flux fed tube. The arc offering between electrod and workpiece us completely submerged under the flux and is not visible from outside. The power source are used with submerged arc welding can be either A.C. or D.C. . The electrod wire is normally used are sizes 1.6 to 2.5 , 3.15 , 4 ,5 , 6.3 and 8 mm .