时效处理对Cr50Ni50Nb合金组织及性能的影响OA

In order to investigate the evolution of heat treatment process on microstructure and mechanical properties of Cr50Ni50Nb alloy,solid solution treatment combined with different aging processes was used to treat Cr50Ni50Nb alloy.The changes in phase,microstructure and mechanical properties of the alloy under different heat treatment states were systematically analyzed through X-ray diffraction,microstructure observation,hardness testing and high temperature tensile testing.The results show that Cr50Ni50Nb alloy is mainly composed of γ(Ni,Cr)solid solution matrix and Cr13Ni5Si2 precipitate phase.The precipitate phase content in solid solution alloy is small,and the number of precipitate phases increases significantly after aging treatment.With the extension aging time,the number of precipitate phases increases and the size becomes larger.Aging treatment can significantly improve the hardness of the alloy,and the hardness gradually increases with the extension of the aging time.The alloy with 800℃×6 h+720℃×8 h aging state has the best high temperature tensile.The strength of the alloy decreased gradually with the increase of the temperature,and the elongation and the area reduction rate showed a trend of decreasing and then increasing,showing obvious medium-temperature brittleness at 700℃.