舰船锅炉过热器用GH984合金中Al、Ti、Nb成分的研究

Study of Al, Ti, Nb Contents of GH984 Alloy Used in Superheater Tube of Naval Vessels

研究了不同Ａｌ、Ｔｉ、Ｎｂ含量对ＧＨ９８４合金性能及γ′相析出的影响。结果表明，随Ａｌ、Ｔｉ、Ｎｂ含量增加，合金的室温拉伸强度、７００℃持久寿命和γ′相数量不断增加。Ｎｂ含量为１．３５％时出现持久寿命峰值。在该合金中Ａｌ、Ｔｉ、Ｎｂ含量（％）分别控制在０．６５、１．２４和１．３５附近时综合性能最佳。合金管材经舰船海上１０年运行考核，完全可以满足舰船长期使用要求。

Abstract The effect of different element (Al, Ti, Nb) contents on mechanical properties and γ′ precipitation of the GH984 alloy has been investigited in this paper. The results show that the tensile strength at room temperature, stress rupture life at 700℃/350MPa and γ′ Phase amount increase with the increment of Al, Ti, Nb contents. At 1.35wt% Nb content, a peak value of stress rupture life at 700℃/350MPa is found in the alloy. To keep the best synthetical properties, the excellent compositions of Al, Ti, Nb contents (wt%) in the alloy should be about 0.65, 1.24 and 1.35 respectively. In order to examine the alloy, the GH984 superheater tube equipped in large scale ship have been operated on sea for ten years. The results show that the GH984 alloy is an excellent anticorrosion superalloy and can fully meet the using requirements of naval vessels for a long time.