Graphite-MoS2-Fe2O3　(Fe3O4)　nano-composite　lubricating　coatings　were　prepared　on　the　surfaces　of　non-copper　coated　solid　wires　by　a　mechanical　coating　technique.　The　tribological　behaviours　of　graphite-MoS2-Fe2O3　(Fe3O4)　coatings　at　the　rubbing　interfaces　of　welding　wires　against　the　contact　tube　were　investigated.　The　results　demonstrate　that　the　lubricating　properties　of　graphite-Fe3O4　coatings　outperform　the　lubricating　properties　of　graphite-Fe2O3　coatings.　The　anti-wear　performance　of　the　contact　tube　is　strengthened　with　increasing　nano-MoS2　contents.　Layers　of　protective　tribofilms　are　formed　at　the　rubbing　interfaces　of　welding　wires　against　a　contact　tube　by　tribochemical　reaction　among　lubricants.　The　tribofilms　are　composed　of　FeO,　MoO3　and　FeMoO4　with　excellent　lubricating　properties.　They　can　avoid　direct　contact　of　welding　wires　against　the　contact　tube,　thus　decreasing　contact　tube　wear.　With　the　transition　of　the　contact　tube　wear　from　mild　to　severe,　the　dominant　wear　mechanisms　of　contact　tube　change　from　fatigue　peeling　and　oxidative　wear　to　abrasive　wear　and　arc　ablation.