Influence of Interlayer Temperature on Microstructure and Mechanical Properties of Stainless Steel Materials in GMA Arc Additive
In order to study the microstructure and mechanical properties of the structure at different interlayer temperatures,the two-channel multi-layer thin-wall structure was surfacing with ER307 stainless steel wire by GMA arc additive technology.The microstructure and mechanical properties of the structure were studied by metallography microscope,microhardness tester and scanning electron microscope.The results show that the microstructures of the samples are composed of γ-Fe and δ ferrite at the interlayer temperatures of 150℃and 220℃.The microstructures in the equilibrium solidification zone are columnar,dendrite and equiaaxial from bottom to height,respectively,and the microhardness in the equiaaxial zone is higher.The average tensile strength of the samples is greater than 600 MPa,and the comprehensive mechanical properties of the longitudinal samples are slightly higher than that of the transverse samples,and there is no obvious anisotropy.With the decrease of interlayer temperature,the size of columnar crystals at the bottom and equiaaxial crystals at the top of the equilibrium solidification zone gradually decreases,the dendrite polarization phenomenon in the middle zone is improved,the adjacent heat affected zone is connected by dendrites and the orientation difference is reduced,the microhardness uniformity is improved,and the longitudinal plasticity and toughness are improved.When the interlayer temperature is 150℃,the equilibrium solidification zone is improved.The yield strength and elongation of the component are 29 MPa and 4.3%higher than that of the interlayer temperature of 220℃.
万方数据
维普
