【摘要】 为了消除粗大 δ铁素体的有害作用 ,研究了用热处理细化 Cr2 5Ni5Mo1 .5双相不锈钢 δ铁素体的方法。热处理所用的反应为 σ化反应 δ→ γ+σ和反 σ化反应 γ+σ→ δ。经过 75 0℃× 38h的 σ化处理 ,δ铁素体转变为细小的 γ相和 σ相的混合组织 ,通过快速加热的反σ化处理 ,获得了非常细小的铁素体。铁素体细化后的 Cr2 5Ni5Mo1 .5双相不锈钢冲击韧性大幅度提高 ,且 5 0℃时的冲击断口形貌由大面积的解理变为细小的韧窝更多还原

【Abstract】 To eliminate the harmful effect of coarse δ ferrite, the method to refine the grain size of the Cr 25 Ni 5Mo 1 5 duplex stainless steel was investigated through heat treatment The reactions employed in the heat treatment were σ reaction δ→γ+σ and anti σ reaction γ+σ→δ The results show through 750℃×38h σ treatment, the δ ferrite transforms to composite of fine γ and σ phases Very fine δ ferrite can be obtained through rapid heating anti σ treatment After refining ferrite, the impact toughness of Cr 25 Ni 5Mo 1 5 increases greatly and the morphology of the fracture surface of the impact sample at 50 ℃ changes from large cleavage to fine dimples更多还原