GB/T8110-1995 "gas shielded arc welding of carbon steel, Copper Alloy Welding Wire" standard applies to carbon steel, low alloy steel melting polar gas using solid welding wire is recommended for gas tungsten arc welding and plasma arc welding the filler metal.
So: If you use different standards, welding wire and two wire security, there are different in composition.
Classification of wire:
1 Purpose: carbon steel wire; low-alloy steel wire; stainless steel wire; alloy welding wire; copper and copper alloy wire; aluminum and aluminum alloy welding wire; cast iron welding wire.
2 points by welding methods: submerged arc welding with wire; welding with wire; gas-shielded welding with wire; electroslag welding with wire.
3, according to the wire cross-section shape and structure: solid steel wire; Welding Wire China.
Mainly carbon dioxide gas shielded arc welding low carbon steel and low alloy steel welding.
TIG weld almost all metals, but mainly for non-ferrous metals and their alloys, stainless steel and some alloy welding.
So, if your weldment of different materials, the selected wire in the composition is not the same.

And copper alloy rod T107, T207, T227, T237 characteristics and uses; T107 for the copper electrode, the better the atmosphere and sea water corrosion resistance, mainly welding conductive copper, copper pipe and other structural parts. T207 is silicon bronze welding rod. Of inorganic acids (except nitric acid), organic acids corrosion resistance, suitable for copper, silicon bronze and brass welding. T227 for the phosphor bronze electrode, there is a certain strength, ductility, toughness, wear resistance and corrosion resistance, suitable for copper, brass, phosphor bronze welding. T237 aluminum manganese bronze rod, wear and corrosion resistance excellent, Welding Wire widely used in copper alloys, aluminum bronze and copper, cast iron welding.
T237 aluminum manganese bronze welding core, medicine for the skin type of copper alloy low hydrogen electrode. Deposited metal containing Al 6.5 ~ 10%, Mn ≤ 2.0%, Cu <90% alloy, wear resistance and corrosion resistance. DC power supply, then the positive electrode. For aluminum bronze and other copper alloys, copper alloys and steel welding and repair Copper Alloy Welding Wire of cast iron. Such as various chemical machinery, water radiator, the valve welding, pumps, cylinders and other surfacing propeller and ship repair. Welding electrodes to be baked at about 200 ℃ 1h. Welding surface of the water, oil, oxides and other impurities must be removed, aluminum bronze and carbon steel welding surfacing, thin pieces without preheating, thick pieces are about 200 ℃ preheating