Short notes on GATE Mechanical Engineering-Important points to remember for Forging
Forging is a very important topic in GATE Mechanical Engineering exam. below we have listed some important points to remember for the chapter of forging.
Important PTRs for Forging:
- In cold working, strain hardening is not relieved.
- In cold working, no oxidation or scaling of work piece surface occurs.
- The hot working is carried above the recrystallization temperature of the material.
- In metal forming process, with increase in temperature, the strength, and hardness of the work-piece decreases with an increase in the ductility.
- Slab method is commonly used in the analysis of metal forming process.
- Cogging, also called drawing out, is basically an open die forging operation in which thickness of a work is reduced by successive forging.
- In open die forging, poor material utilization occurs. In closed die forging, impressions are cut in the die block and no flash is produced.
- In impression die forging, the work piece acquires the shape of die cavities while being forged between two shaped dies and flash is produced.
- In fullering, the material is distributed away from an area.
- In edging, the material is gathered in a localized area.
- In precision forging, special dies produce parts having greater accuracies than those from impression die forging and requiring much less machining.
- Forging ensures directional properties to be obtained by controlling the fibre flow directions. As a result, many engineering components that are required to withstand heavy forces are produced using forging process.
- Extrusion is similar to rolling in producing a constant cross section area shapes. However, extrusion allows the production of complex shapes by using a minimum number of passes.