Effect of surface hardness in tensile testing

Hi Everyone,

 Is is possible to account the surface hardness effect in the tensile testing specimen? If possible, how could it be acomplished?

For instance, I would like to establish the  stress strain curve for the material that used on surface hardened component. Will there be a big change if the surface hardness effect is considered on the tensile specimen?

Please throw some light in this regard.

Thanks

M Gopalakrishnan