The Effect Of Rare Earth Ce On The Hot Deformation Behavior Of White Copper BFe10-1.5-1 Alloy

Cupronickel alloy has excellent mechanical properties and corrosion resistance.It's widely used in marine equipment,petrochemicals,shipbuilding and other fields.In recent years,B10,B19,B30 and other series of cupronickel alloys have been developed.Among them,BFe10-1.5-1 alloy has better corrosion resistance due to the addition of Fe and Mn elements.Rare earth elements attracts the attention of scholars because they can purify alloy melts,refine grains,and improve the overall performance of alloys.The research of rare earth in BFe10-1.5-1 alloy is relatively rare,and the related mechanism is still unclear.Based on this,the hot deformation behaviour of BFe10-1.5-1 alloy was studied by thermal-simulation technology in this article.And the constitutive equation and processing map were established to compare and analyse the effacts of Ce on hot deformation behavior of BFe10-1.5-1 alloy.The influence of rare earth elements on the microstructure evolution during thermal processing was discussed,and the structure-activity relationship between microstructure and thermal processing properties was clarified.It indicates the following conclusions:?1?The addition of Ce can refine the dendrites of BFe10-1.5-1 alloy,and the effect is better when the Ce content is 0.014wt.%.After the thermal deformation,the spherical rare earth second phase was observed in the microstructure of the alloy when the content of Ce is0.044wt.%.The phase is CeCu₆ phase and the size of it is 300⁵00nm.?2?When the deformation temperature is less than 950?,the addition of Ce can increase the flow stress of BFe10-1.5-1 alloy;when the temperature is higher than 950?,the flow stress of the alloy which contains 0.014wt.% Ce is still higher than that excluded Ce.The flow stress of the alloy which contains 0.044 wt.% Ce is lower than that excluded Ce.The flow stress curve of the alloy did not show obvious peak stress in the experiment.So the equivalent strain method was used to construct the constitutive equation of BFe10-1.5-1 alloy with different Ce content,which can accurately predict the thermal deformation law of the alloy.And the result shows it fits well.?3?The processing map based on the dynamic material model shows:The safe processing range of BFe10-1.5-1 alloy is 850¹000? in temperature,0.01⁰.4s^-1 in strain rate,and the dangerous processing range is 850¹000?,1¹0s^-1.When the Ce content is0.014wt.%,the optimum processing area of the alloy is 910¹000?,0.01⁰.3s^-1,and the optimum processing area is 850⁹60?,0.01⁰.4s^-1 when the Ce content is 0.044wt.%.?4?In the same thermal deformation condition,the addition of Ce promotes the dynamic recrystallization of BFe10-1.5-1 alloy.The degree of recrystallization of the alloy with0.044wt.%Ce is higher than the alloy with 0.014wt.% Ce.And the former has completely recrystallized in 850?,0.01 s^-1.The reason is that the CuCu₆ phase formed by Cu and Ce has a pinning effect on the dislocations,which can significantly hinder the dislocation motion,increase the dislocation density rapidly,and promote the nucleation of dynamic recrystallization.