QPQ　salt　bath　treatment　of　SAF2906　duplex　stainless　steel　was　conducted　at　570　°C　for　60　min,　90　min,120　min,150　min　and　180　min,　followed　by　post-oxidation　process　with　heating　temperature　of　400°C　and　holding　duration　of　30　min.　The　effect　of　QPQ　nitriding　time　on　microstructure　and　wear　resistance　of　SAF2906　duplex　stainless　steel　was　investigated　by　means　of　OM,　SEM,　XRD,　microhardness　test,　adhesion　strength　test　and　wear　resistance　test.　Microstructure　observation　showed　outer　layer　was　composed　of　Fe3O4.　The　main　phase　of　the　intermediate　layer　was　CrN,　αN　and　Fe2-3N.　The　main　phase　of　the　inner　layer　was　CrN　and　S.　The　adhesion　strength　test　of　the　surface　layer-substrate　showed　the　QPQ　treated　samples　have　favorable　adhesion　strength　of　HF-1　level.　With　the　increase　of　nitriding　time,　the　growth　rate　of　the　compound　layer　gradually　slowed　down　and　the　surface　hardness　first　increased　and　then　decreased,　and　the　maximum　hardness　was　1283　HV0.2　at　150　min.　The　dry　siliding　results　showed　that　the　wear　resistance　of　the　QPQ　treated　samples　was　at　least　20　times　than　that　of　the　substrate,　and　the　optimum　nitriding　time　to　obtain　the　best　wear　resistance　is　150　min.　The　worn　surface　morphology　observation　showed　the　main　wear　mechanism　of　the　substrate　was　plough　wear,　while　micro-cutting　is　the　main　wear　mechanism　that　causes　the　damage　of　the　QPQ　treated　samples.　©　Published　under　licence　by　IOP　Publishing　Ltd.