Transformer arrangement (100; 600) comprising a welding transformer , which has a primary winding and a secondary winding (133; 409) and in which is arranged at least one coil turn with a current-conducting component as part of the secondary winding , wherein the current-conducting component consists of aluminium or an aluminium alloy, wherein the current-conducting component has a cavity formed in its interior for receiving a cooling fluid, and wherein at least one means for protecting the current-conducting component against corrosion, in particular for protection against corrosion caused by the cooling fluid, is provided, connection pieces embodied as carrier components of the coil turn of the secondary winding , wherein the connection pieces consist of aluminium or an aluminium alloy and have a coating , and two rectifier assemblies , wherein a rectifier assembly is electrically connected to at least one of the connection pieces and has a first connection plate for a rectified output voltage, wherein a second connection plate is connected to one of the connection pieces , wherein at least one of the connection plates has a coating , wherein the connection pieces together with two rectifier assemblies and optionally the connection plates constitute an output rectifier arrangement , wherein openings of the cavity in the interior of the current-conducting component are connected to openings of the connection pieces via conduit channels, wherein the entire transformer arrangement (100; 600) including the output rectifier arrangement is assembled by being screwed together, wherein the coating of the connection pieces is nickel and a coating on electrical contact surfaces of the current-conducting component is nickel, with the result that the formation of an aluminium oxide layer between the connection pieces and the current-conducting component is prevented, and wherein a coating in the interior of the current-conducting component is nickel and/or aluminium oxide, wherein the at least one means for protecting the current-conducting component against corrosion comprises the coating on the electrical contact surfaces and the coating in the interior of the current-conducting component. connection pieces embodied as carrier components of the coil turn of the secondary winding , wherein the connection pieces consist of aluminium or an aluminium alloy and have a coating , and two rectifier assemblies , wherein a rectifier assembly is electrically connected to at least one of the connection pieces and has a first connection plate for a rectified output voltage, wherein a second connection plate is connected to one of the connection pieces , wherein at least one of the connection plates has a coating , wherein the connection pieces together with two rectifier assemblies and optionally the connection plates constitute an output rectifier arrangement , wherein openings of the cavity in the interior of the current-conducting component are connected to openings of the connection pieces via conduit channels, wherein the entire transformer arrangement (100; 600) including the output rectifier arrangement is assembled by being screwed together, wherein the coating of the connection pieces is nickel and a coating on electrical contact surfaces of the current-conducting component is nickel, with the result that the formation of an aluminium oxide layer between the connection pieces and the current-conducting component is prevented, and wherein a coating in the interior of the current-conducting component is nickel and/or aluminium oxide, wherein the at least one means for protecting the current-conducting component against corrosion comprises the coating on the electrical contact surfaces and the coating in the interior of the current-conducting component. <EOS>