Design Of New Supporting Roller Hardfacing Alloy And Research On The Tempering Heat Treatment

Hot-rolled supporting roller is easy to crack or even desquamate after serving for a long time,which is mainly caused by abrasion.Due to the long production cycle and high production costs of a new-produced supporting roller,the disabled supporting roller can be repaired and reapplied by hardfacing technique.In this paper,the effect of elements such as Ni,Mn,Mo and V on the microstructure of hardfacing alloy was studied by thermodynamic calculation.On this basis,a new type supporting roller hardfacing alloy was designed and the designed composition is:?0.3⁰.5?wt.%C+?5.0⁶.0?wt.%Cr+?1.0¹.5?wt.%Ni+?2.0².5?wt.%Mo+?0.4⁰.5?wt.%V+?1.5².0?wt.%Mn+?0.6⁰.8?wt.%Si+Fe.Based on the designed composition,flux-cored wire was fabricated and then hardfaced on substrate.The microstructure of the hardfacing alloy is made up by acicular martensite,high alloy martensite,retained austenite,M₇C₃ and MC.In order to determine the tempering treatment process of the hardfacign alloy,the microstructures and properties of the hardfacing alloy treated at different temperatures and after different times are compared.The cold hardening effect during service is also analyzed.The optimum tempering treatment process of the new type supporting roller hardfacing alloy is treated at540?for 4h,and then cooled by air.According to the designed composition of the new type supporting roller hardfacing alloy,YD254M flux-cored wires are produced and subsequent application research is carried out.The using conditions and performances of the repaired supporting rollers show that the hardfacing alloy prepared by YD254M flux-cored wires can meet the performance requirements.Compared to a new-produced supporting roller,the production costs and production cycle can be greatly reduced.