Ⅰ.前言TCP 相(Topologically Close-PackedPhases)即拓扑密排相,是镍基、钴基、铁基高温合金以及奥氏体不锈钢中常见的析出相。σ、μ、R,Laves 相等都属此列。一般情况下,它们是一种有害相。早在二次大战期间,人们就发现σ相对铁基奥氏体合金的危害性。到了六十年代初,Woldek 和 Ross 又在 In-100镍基合金中发现:σ相降低了合金的断裂强度和延伸率。不锈钢中如出现σ相还会引起晶界腐蚀,降低材料的耐腐蚀性能。所以长期以来冶金工 Ⅰ. Preface TCP (Topologically Close-Packed Phases) is a topologically dense phase that is a common precipitated phase in nickel-based, cobalt-based, iron-based superalloys and austenitic stainless steels. σ, μ, R, Laves are equal to this column. In general, they are a harmful phase. As early as during the Second World War, people discovered the danger of σ relative to iron-based austenitic alloys. By the early 1960s, Woldek and Ross found in In-100 nickel-base alloys that sigma phase reduced the alloy’s breaking strength and elongation. The presence of sigma phase in stainless steel also causes grain boundary corrosion and reduces the corrosion resistance of the material. So for a long time metallurgical workers