Abstract: The wear resistant welded surfacing layer is prepared on 45CrNiMoVA steel with UTP A DUR600 wear resistant weld wire by means of pulse metal inert-gas arc welding technology. The microstructure of welded surfacing layer is observed and analysed by scanning electronic microscopy(SEM); And the microhardness and wearing resistance are tested. The results show that the microstructure of welded surfacing layer is mainly composed of austenite and secondary cementite; The welded surface layer has higher microhardness and more excellent wearing resistance than 45CrNiMoVA steel substrate; The existence of hard secondary cementite, the work hardening of austenite and fragmentation, dynamic oxidation and hot pressed sintering of abrasive dust are mainly reasons which make welded surface layer possess more excellent wearing resistance.

Key words: 45CrNiMoVA steel, Frictional wear, Metal inert-gas arc welding