| In modern industry, the cost caused by wear and impacts has sharply increaseddue to the harsh working environment. The traditional wear-resistant materials cannotmeet the need of the wear requirement and most of are not crack resistant. In order tosolve the problem, Fe-Cr-B hardfacing alloy with different B, Ti, C, Ni contents aredeposited with CO2gas shielded welding method. It has high hardness and good wearresistance due to its microstructure characteristics which are studied by OM, SEM,EDS, XRD and wear test techniques. It is shown that:The Fe-12Cr-xB-0.1C hardfacing alloys are composed of ferrite, austenite,martensite,（Fe-Cr） solide solution,（Fe,Cr）7C3,（Fe,Cr）2B and （Fe,Cr）23（B,C）6. It isshown that with the increase of B content, the volume of borides and microstructurechanged a lot. The number of primary （Fe,Cr）2B increased gradually and the sizereduced, evenly distributed.The hardness of the hardfacing alloy can reach67HRC atmost, and the wear resistance was first increased then decreased. The relative wearresistance with4%B is6.67, however it has poor crack resistance ability.With addition of appropriate Ti and0.7%carbon, the （Fe,Cr）3（B,C） phase isfound in the alloy and small TiC particles with highly microhardness are formedamong hard phases, sharply deduced the brittleness of hardfacing alloy, doubled thewear resistance ability. Both the size and number of TiC particles are increased withTi content increasing in the alloys with constant C content （0.7%）. However the alloyswith the same Ti content （0.9%） and different C content show that with the increase ofC, the quantitative changes of TiC particles are small, only the size increased. Toomuch of TiC in the hardfacing alloy would cause mocrospalling, is detrimental tohardfacing alloy’s wear resistance.Another way to improve the alloy’s fracture resistance ability is better theductility of the alloy’s matrix, in this paper with the addition of Ni, the cracks ofwelding are effectively deduced. |
PDF Full Text Request