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A new kind of coating preparation technology--- tungsten nitrogen arc surfacing welding process（national patent:200910074595.4） is proposed.Which Connected tungsten nitrogen protection welding technique with in-situ synthesized technology organically, high temperature of the nitrogen arc made the N2 and pre-applied powder reacted,in the process of which metal ceramic coating were generated..With the industrial N2 （purity 99.999%） （as the protection gas and reaction gas）and tungsten for electrode extremely, the metal ceramic coating of TiCN were prepared on the surface of Fe base by the TXⅡ500 argon arc welding machine.The hardness and XRD of layer were Researched in different content percent of Fe power and the best Mixture ratio（Ti: C: Fe = 1: 1:1） was obtained.Effects on macromorphology and microhardness of the coating in the different current, welding speed, flow rate of nitrogen were analysed..the results show that, the surface of the coating was good. But, the hardness of coating was low because of the penetration ratio was high and the molten metal dilutied the coating; when welding speed was 2mm/s and 3mm/s, pre-covered coating absorbed more heat, alloy elements spreaded fully, which formed more hard phase particles were formed and the mirohardness was high; nitrogen flow speed of nitrogen had great influence on intrinsic properties and have little relationship with surface quality of Coating ,when the nitrogen flow speed of nitrogen reached 20L/min,more were fast,the nitrogen provided more, TiCN particles of TiCN were formed more especially when nitrogen flow speed reached 20L/min,and the coating hardness of coating could reach up to HV0.21610.Forming process of the TiCN were analysed,the microstructure,elements distribution and the phase of section coating and surface coating were also analyzed. The results show that,coating,combined area,matrix presented metallurgical combination obviously, cracks, slag inclusion, incomplete fusion phenomenon were not found from the coating; the elements of Ti, C, N, Fe and O were found in the coating, elements distributed unevenly and N element were less. Under the conditions of this experiment,TiC0.51N0.12 were tend to form on （102）, （014） crystal, when the current was 200 A and the flow speed of nitrogen was 20 L/min the peak value were highest in XRD energy spectrum;when welding speed was 2-3 mm/s, The content percent of TiC0.51 N0.12 was the highest.The law of current, cladding speed, nitrogen flow on the molten coating wear resistance was researched. The results show that, friction coefficient of coating exist big difference because of different process parameters,especially flow speed of nitrogen and welding speed was great, the wear resistance of the coating and substrate were compared under the same conditions,The weightlessness of coating was about 1/10 of the matrix. The optimal scheme for molten coating wear was obtained with the orthogonal experiment: welding current was 200 A, tungsten polar diameter was 1.6 mm, nitrogen flow was 12 L/min, cladding speed was 2 mm/s, welding thickness was 1.5 mm.In order to improve the coating performance further,The powder of Al were added into the pre-covered powder.TiAl（CN） coating were formed by tungsten nitrogen arc welding technology, the result show that,the coating were smooth, and present a metallurgical bonding with the substrate, micro hardness of up to HV0.51710, coating wear resistance improved significantly compared with TiCN coating at the same conditions of preparation.
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