Strain hardening

Question

Question

This question was previously asked in

BPSC AE Paper 6 (Mechanical) 14 Oct 2022 Official Paper

Answer 1

Explanation:

Strain hardening:

When yielding has ended, a further load can be applied to the specimen, resulting in a curve that rises continuously but becomes flattered until it reaches maximum stress referred to as ultimate stress. The rise in the curve is known as strain hardening.

F2 J.S 3.7.20 Pallavi D3

Strain hardening is the strengthening of a metal or polymer by plastic deformation. The strengthening occurs because of dislocation movements and dislocation generation within the crystal structure of the material.
Strain hardening increases the strength of the metal, including its hardness and tensile strength. It also decreases the ductility of the metal, meaning that it becomes less able to deform without cracking or breaking. However, it does not decrease the yield strength of the metal.
In a strain-hardening material stiffening effect is felt at some stage. The strain hardening region is shown in the figure above. The yield plateau describes the amount of plastic flow.
Strain hardening in the case of steel occurs between yield strength and ultimate strength.