Cyclic Deformation Behavior and Fatigue Crack Propagation of Low Carbon Steel Prestrained in Tension

Figure 2

Saturation dislocation structure of specimens at various plastic strain amplitude with different preloading conditions (a) 𝜀_pl=0.6×10⁻³, non-prestrained, 𝜙=0^∘; (b) 𝜀_pl=0.6×10⁻³, 10% tension prestrained, 𝜙=0^∘; (c) 𝜀_pl=2.5×10⁻³, 2% tension prestrained, 𝜙=45^∘; (d) 𝜀_pl=1.5×10⁻³, non-prestrained, 𝜙=0^∘; (e) 𝜀_pl=2.5×10⁻³, 10% tension prestrained, 𝜙=0^∘; (f) 𝜀_pl=2.5×10⁻³, 10% tension prestrained, 𝜙=45^∘. RD = rolling direction, TD = testing direction, and MB = microband.

(a)

(b)

(c)

(d)

(e)

(f)