Hammering and shaping a hot steel block on an anvil is anexample of: a) Open-die forging. b) Closed-die forging. c)Flashless forging. d) Impression die forging.
Resistance spot welding can be used to join sheets of _______and_______. a) Rubber, steel. b) PVC plastics, copper. c) Stainlesssteel, leather. d) None of the above.
An advantage of forward extrusion over backward extrusion is: a)Lower pressure. b) Lower force. c) All of the above. d) None of theabove.
In a rolling process, if both roller diameters reduce by 25%,then the required power to rotate the rollers would: a) Increase25%. b) Decrease 25%. c) Increase 50%. d) Decrease 50%.
Which of the following bulk deformation processes are involvedin the production of nails for lumber construction? a) Wiredrawing, flashless forging, and impression die forging. b) Wiredrawing, flashless forging, and rolling. c) Flashless forging,impression die forging, and upsetting. d) Extrusion, flashlessforging, and wire drawing
The thickness of each of the two sheets to be resistance spotwelded is 3.5 mm. It is desired to form a weld nugget that is 5.5mm in diameter and 5.0 mm thick after 0.3 sec welding time. Theunit melting energy for a certain sheet metal is 9.5 J/mm3 . Theelectrical resistance between the surfaces is 140 micro ohms, andonly one third of the electrical energy generated will be used toform the weld nugget (the rest being dissipated), determine theminimum current level required.
A GTAW operation is performed on low carbon steel, whose unitmelting energy is 10.3 J/mm3 . The welding voltage is 22 volts andthe current is 135 amps. The heat transfer factor is 0.7(convection heat loss of 30%) and the melting factor is 0.65(conduction heat loss of 35%). If filler metal wire of 3.5 mmdiameter is added to the operation, the final weld bead is composedof 60% volume of filler and 40% volume base metal. If the travelspeed in the operation is 5 mm/sec, determine:
(a) The cross sectional area of the weld bead
(b) The feed rate (mm/sec) at which the filler wire must besupplied.
