🔩 Flanging (Edge Forming) Flanging involves bending the edge of a sheet or plate beyond its elastic limit into the plastic region of the stress–strain curve. What’s happening internally? • The applied stress exceeds the material’s yield strength • Dislocation density increases (defects in the crystal lattice multiply) • Grains elongate in the direction of strain • Work hardening (strain hardening) occurs This localized plastic deformation increases edge stiffness and geometric rigidity without adding material. The flange acts like a reinforcing rib, improving: • Section modulus • Buckling resistance • Fatigue performance (if properly formed) • Assembly precision However, excessive strain can cause: • Edge cracking (especially in low-ductility alloys) • Thinning due to tensile stretching • Residual stress concentrations 📏 Straightening (Stress Redistribution) After machining, welding, or forming, internal residual stresses remain locked inside the material due to non-unifo...