**4.3. Hardening coefficients**

Slip induced hardening is another important factor influencing the limit strains. From Eqs. (28) and (29) it is easy to see that the parameters *h*0 and *n* govern the strain hardening. We investigated the effect produced by different values of the hardening coefficient *n* (0.16, 0.19 and 0.23) while fixing the other material properties. The calculated FLDs are shown in Fig. 7, where it is clear that the slip hardening coefficient *n* does not affect the shape of the forming limit curves. However, it can be seen that the largest value of *n* produces the highest limit strains. Also, no noticeable dependence with ρ is observed. Because we use isotropic hardening in these calculations, the *n* parameter only guides the stress level, producing these simple behaviors. This will not be the case when latent hardening and other kinematic effects are included in the calculations.
