Study on weldability and microstructure performance of new Ni-Fe based high temperature alloy
This article has prepared a new type of Ni-Fe-based high-temperature alloy(HT700)butt joint by using manual TIG welding with FM700-1 welding wire.Through the analysis of the macroscopic organization and microscopic morphology of the welded joint,it was found that there was an unevenness of microstructure and mechanical properties in the welding micro-region.The grains of the material near the fusion line were significantly coarsened,and dendritic segregation was found in the weld.The hardness and strength of the heat-affected zone and the weld were higher than those of the base material.Excessive welding heat input caused hot cracks in the heat-affected zone and the weld.The conclusions were as follows:(1)The weld microstructure was typical columnar γphase,and there was a significant dendritic segregation phenomenon in the organization.(2)The mechanical properties of the welded joint micro-region showed a gradient distribution characteristics,which was mainly related to its microscopic unevenness.(3)The welding heat input in the foundation area was too large,resulting in the occurrence of hot cracks in the heat-affected zone and the weldment in this area,while the welding heat input in the filling area was smaller,and no hot cracks were found in the weldment and heat-affected zone.
new Ni-Fe alloy(HT700)butt joinwelding performanceweld microstructure
万方数据
维普
