[en] We spectroscopically survey the galaxy cluster XMM-LSS J02182-05102 (hereafter IRC 0218) using LRIS (optical) and MOSFIRE (near-infrared) on Keck I as part of the ZFIRE survey. IRC 0218 has a narrow redshift range of $1.612<<!--\; <\; -->$ $z_{\mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}}$ $<<!--\; <\; -->1.635$ defined by 33 members of which 20 are at R${}_{\mathrm{p}\mathrm{r}\mathrm{o}\mathrm{j}}$ $<<!--\; <\; -->1$ Mpc. The cluster redshift and velocity dispersion are $z_{\mathrm{c}\mathrm{l}}=1.6233\pm <!--\; ??\; -->0.0003$ and ${\mathrm{\sigma <!--\; ??\; -->}}_{\mathrm{c}\mathrm{l}}=254\pm <!--\; ??\; -->50$ km s⁻¹. We reach NIR line sensitivities of ∼0.3 × 10⁻¹⁷ erg s⁻¹ cm⁻² that, combined with multi-wavelength photometry, provide extinction-corrected Hα star formation rates (SFR), gas phase metallicities from [N ii]/Hα, and stellar masses. We measure an integrated Hα SFR of ∼325 $M_{\odot <!--\; ???\; -->}{\mathrm{y}\mathrm{r}}^{-<!--\; ???\; -->1}$ (26 members; R${}_{\mathrm{p}\mathrm{r}\mathrm{o}\mathrm{j}}$ $<<!--\; <\; -->2$ Mpc) and show that the elevated star formation in the cluster core (R${}_{\mathrm{p}\mathrm{r}\mathrm{o}\mathrm{j}}$ $<<!--\; <\; -->0.25$ Mpc) is driven by the concentration of star-forming members, but the average SFR per Hα-detected galaxy is half that of members at R${}_{\mathrm{p}\mathrm{r}\mathrm{o}\mathrm{j}}$ ∼ 1 Mpc. However, we do not detect any environmental imprint when comparing attenuation and gas phase metallicities: the cluster galaxies show similar trends with $M_{\star <!--\; ???\; -->}$ as to the field, e.g., more massive galaxies have larger stellar attenuation. IRC 0218’s gas phase metallicity–$M_{\star <!--\; ???\; -->}$ relation (MZR) is offset to lower metallicities relative to $z\sim <!--\; ???\; -->0$ and has a slope of 0.13 ± 0.10. Comparing the MZR in IRC 0218 to the COSMOS cluster at z = 2.1 shows no evolution ($\mathrm{\Delta <!--\; ??\; -->}t\sim <!--\; ???\; -->1$ Gyr): the MZR for both galaxy clusters are remarkably consistent with each other and virtually identical to several field surveys at $z\sim <!--\; ???\; -->2$.