Question

6.1. How does extrusion differ from rolling and forging? 10

Answer 1

chos Exlusima Ealansion is the proces of pushing the hearted Bilet of metal though an orifice provided into a die, thus forming an elongated part of uniform section exverponding to be hope of the die The pressuve is applied hydraulically or mechanically. Intricate shapes of long lengths can be produced by hat extrusion. Depending on the die lility of material, extrusion may be carried out est room or elevated lempovatune. Forging Forging in the shaping of metals by squee- zing them between two or more dies to estain the desired shape. Forging can be done at roonn temperature or at elevated temperature of the harging operation is carried out below the neer- go to elization temp it is known as cold forging and if at abone veerystallization temp is called hat forging. Forging defects & Cracks 1 1 n Fold in Barreling

wo oma Rolling of Cerain stone ture of the metal changes when it passes through the rolls. As a result of squeezing the growing are elongated in the dinection of rolling and relocity of the materin al at exit is higher than and the entrins. After crossing the stress sone the grains start befinn refining. But this is the case only in the hot rolling In the conhel rolling they tend to retain the shape aquined by them during nothing Rolling defects of it Wary edges in) Crocodile crack nisl