OCCASO - III. Iron peak and a elements of 18 open clusters. Comparison with chemical evolution models and field stars

The study of open-cluster chemical abundances provides insights on stellar nucleosynthesis processes and on Galactic chemo-dynamical evolution, En this paper we present an extended abundance analysis of 10 species (Fe, Ni, Cr, V, Sc, Si, Ca, Ti, Mg, O) for red giant stars in 18 OCCASO clusters, This represents a homogeneous sample regarding the instrument features, method, line list and solar abundances from confirmed member stars, We perform an extensive comparison with previous results in the literature, and in particular with the Gala FGK Benchmark stars Arcturus and mu-Leo. We investigate the dependence of [X/Fe] with metallicity, Galactocentric radius (6.5 kpc < R-GC < 11 kpc), age (0.3 Gyr < Age < 10 Gyr), and height above the plane (vertical bar z vertical bar < 1000 pc). We discuss the observational results in the chemo-dynamical framework, and the radial migration impact when comparing with chemical evolution models. We also use APOGEE DR14 data to investigate the differences between the abundance trends in R-GC and vertical bar z vertical bar obtained for clusters and for field stars.