Question

2. What are the three stages of the annealing process? What effects would annealing have on the properties and microstructure of a strain hardened piece of material?

Answer 1

LEHELE Annealing & O Annealing is one of the most important widly-wed operation in the heard treatment of the steel. 1. The purpose of annealing is to obtain softness, improve machine ability, increase or restore ductility and toughnen, releante internal streme, recuere or eliminate strutural inhomogeneity, dele refine grain size, and the prepare steel for subsequent heat treatment. There are three stage of annealiny ♡ Recovery ② Recrystallization ☺ Gruin Growth. Temperature de Gouin growth Recrystallizaton Reco STADT 0 Recovery & The relief of some of the internal struin energy of a I proviously cold worked material ① Recrystallization. The formation of now set of struin - free grain within a previously cold- worked material.) Gowin Growth & The increme in avenue grain size of polycrystal material | I

propedie. ito Munneling. shayari olleet the mechanical Anneultry tempo strenyth Ductility (7.EL) * The cold worked stage State i thermodynamically unstable * With increasing temp? it become more and more unstable * Evantuully the metal softens and returns to a stowin free condihin lensile $ Recrystallization Gruin Recovery Growth & Effect on microstructure Recovery & the relife of some internal struin energy of a prevjusly cold work ! Complete phese recrystallization of hypereutestoid steel (full annealing) is required only in at cases when hot working (rolling or forging was finished at high tempratures and the steel & coarer gruined. p ovucne (a) cold worked (b) ofter recovery (c) Afte recrystallira hion (d) ofter groin growth