Comprehensive abundance analysis of red giants in the open clusters NGC
  752, NGC 1817, NGC 2360 and NGC 2506
  We have analyzed high-dispersion echelle spectra ($R \ga 50,000$) of red
giant members for four open clusters to derive abundances for many elements.
The spread in temperatures and gravities being very small among the red giants
nearly the same stellar lines were employed thereby reducing the random errors.
The errors of average abundance for the cluster were generally in 0.02 to 0.07
dex range. Our present sample covers galactocentric distances of 8.3 to 10.5
kpc. The [Fe/H] values are $-0.02\pm$0.05 for NGC 752, $-0.07\pm$0.06 for NGC
2360, $-0.11\pm$0.05 for NGC 1817 and $-0.19\pm$0.06 for NGC 2506. Abundances
relative to Fe for elements from Na to Eu are equal within measurement
uncertainties to published abundances for thin disk giants in the field. This
supports the view that field stars come from disrupted open clusters.
