34.6 Strain Hardening (Work- harden ng I. What's strain harden ing (work ing hardening By strain hardening we means the increase in tensile stress for polycrystals or in shear stress(the flow stress) for single crystals necessary for keeking on plastic deformation§4.6 Strain Hardening (Work￾hardening) ◆Ⅰ.What’s strain hardening ? (working hardening) By strain hardening we means the increase in tensile stress for polycrystals or in shear stress (the flow stress) for single crystals necessary for keeking on plastic deformation