作　　者： ; ;

机构地区： 上海大学材料科学与工程学院材料研究所

出　　处： 《金属学报》 2001年第1期8-12,共5页

摘　　要： 应用透射电子显微镜（ＴＥＭ）研究了６９０合金经固溶热处理，及经不同温度（６００－８００℃）和不同时间（０．５－２００ｈ）时效热处理后的显微组织结。果表明：６９０合金经过固溶处理及时效热处理后，在晶界上析出面心立方结构的碳化物 Ｍ２３Ｃ６；碳化物优先在晶界位错缠结处成核，在大角度晶界处，一侧晶粒的（１００）晶面与界面接近平行时碳化物更容易析出；晶界上析出的碳化物总是与同一侧的基体有立方－立方的共格取向关系；碳化物不在孪晶面上析出，但会在孪晶端头的非共格界面上析出，析出后沿〈１１０〉生长较快，形成针状：通过特殊热处理可以控制和调节晶界碳化物的长大和贫Ｃｒ区中的Ｃｒ含量，以获得最佳耐腐蚀性能． The microstructures of alloy 690 after solid solution treatment followed by aging treatments at different temperatures (600-800 degreesC) for various times (0.5-200 h) have been investigated by means of transmission electron microscopy (TEM). The results are as follows: the carbides precipitated on the grain boundaries have been identified as M23C6; the carbides nucleate preferentially at the positions where grain boundary dislocations tangled and easily precipitate in high angle grain boundaries nearly parallel to the (100) plane of grain on one side. The carbides always exhibit a cube-on-cube orientation relationship with matrix of one side, and don't precipitate on twinning plane but easily precipitate on the non-coherent boundaries of twin end where carbides grow fast along < 110 > direction and appear as needlelike. By controlling the growth of carbides and the content of chromium in depleted zone by special heat treatments, the corrosion resistance of alloy 690 can be optimized.

关 键 词： 合金 热处理 显微组织 碳化物 压水反应堆 镍合金 蒸汽发生器

领　　域： [核科学技术] [金属学及工艺] [一般工业技术] [金属学及工艺]