焊接工艺与微合金化对铝青铜堆焊组织及性能的影响OA

In response to issues such as complex interface reactions,concentrated stress on the bonding surface,and severe impact on the welding performance of heterogeneous materials,the effects of cold metal transfer(CMT)process,pulse process,and microalloying on the microstructures and bonding strength of S215 and S216 aluminum bronze were studied.The results indicated that both welding modes achieved good metallurgical bonding at the interface of aluminum bronze and steel matrix,and fractures occurred on the copper side.In CMT mode,as the welding heat input decreased,the microstructures of S215 were affected.The α phase was finer and the sec-ond phase was more dispersed.Bonding strength increased by about 38 MPa compared with the pulse mode.Under the same welding parameters,the results obtained for S216 were opposite to those obtained for S215.In S216 alloy,with the solid solution addition of Mn and Ni elements,melting point of the alloy decreased,and more welding heat was absorbed by the steel matrix under the same welding parameters.Therefore,in pulse mode,the diffusion of Fe element from the steel matrix to the copper-based brazing filler metals domi-nated.Heterogeneous nucleation and Fe element enrichment at grain boundaries by Fe element diffusion shaped α phase grains to be fine columnar and equiaxed.Pinning of dislocations was further intensified,increasing bonding strength by about 32 MPa over CMT mode.