The Effect Of Al,Ti Addition On Surfacing Strengthening Composite Mteal Alloy

Since the reform and opening up,the combination of laser technology,computer technology and new material technology has brought up a new era of surfacing.The preparation of wear-resistant materials by surfacing technology has been developed rapidly with the increase of industrial wear resistance demand and it has become one of the most economical mtethod of surface strengthening.In this paper,two surfacing methods of submerged arc strip welding and flux cored welding wire were used to prepare Fe-Cr-C-N-Ti and Fe-Cr-C-N-Al wear-resistant composite strengthening alloy.The difference of element transition between two welding methods was compared.Different hard phases in different alloy systems and their distribution in composite strengthening alloy were discussed.The influence of different hard phases on the microstructure of composite strengthening alloy was analyzed.The effect of hard phase on hardness and wear mechanisms of strengthening alloy under two alloy systems were also studied.Flux cored wires of Fe-Cr-C-N-Al and Fe-Cr-C-N-Ti systems were prepared.The hardness of the composite strengthening layer prepared by Fe-Cr-C-N-Al flux cored wire reached 64.5 HRC and the minimum wear loss reached 00..007744 gg..TThhee mmaaxxiimmuumm hhaarrddnneessss aanndd the minimum wear rate of the composite strengthening layer prepared by Fe-Cr-C-N-Ti flux cored wire are 63.4HRC and 0.106g.The wear-resistant composite strengthening alloy of Fe-Cr-C-N-Al was prepared by submerged arc strip welding experiment.The rational design of the slag was designed out.Owing to the low transition coefficient,there were almost no Al and N elements in the composite strengthening layer,so no cermet hard phase of AlN was formed.However,bright white composite carbonitride?Cr,Fe?₇?C,N?₃ was found in the composite strengthening layer.And with the increase of Cr element,its quantity also increases.?Cr,Fe?₇?C,N?₃ composite carbonitrides were mostly irregular polygons and rods.Abrasive wear test showed that,?Cr,Fe?₇?C,N?₃ composite carbonitrides can improve the wear resistance of composite strengthening layer,and its wear resistance was related to the quantity and distribution of composite carbonitride.Fe-Cr-C-N-Al wear-resistant composite strengthening alloy was prepared by flux cored wire welding.The microstructure of the composite strengthening alloy was acicular martensite+residual austenite+eutectic carbide+Ceramic hard phase of AlN.The ceramic hard phase of AlN precipitated along the austenite grain boundary and distributed in the matrix with regular quadrilateral distribution.AlN cannot be the heterogeneous nucleation particle of M₇C₃.The existence of hard phase ceramics of AlN improves the wear resistance of composite strengthening alloy.Under the combined action of AlN and eutectic carbide,the wear resistance mechanism is superior to that of a single composite carbide hard phase.Fe-Cr-C-N-Ti wear-resistant composite strengthening alloy was prepared by open-arc self-shielded flux-cored wire welding.Ti?C,N?carbonnitrogen composite hard phase synthesized in-situ in composite strengthening layer.With the increase of Ti content,the number of Ti?C,N?carbonnitrogen hard phases were also increased.Most of the hard phases were distributed in the grains and a few along the grain boundaries.Ti?C,N?carbonnitrogen composite can be the heterogeneous nucleation particle of M₇C₃,which provides the possibility for the growth of M₇C₃ and refines its grain.The wear-resistant skeleton composed of Ti?C,N?carbonnitrogen composite and eutectic carbide can effectively improve the wear resistance of Fe-Cr-C-N-Ti composite strengthening alloys.