张源虎
,
项毅
,
孙坚
,
胡赓祥
,
李铁藩
金属学报
本文应用扫描电镜、剖面分析及EDAX能谱分析,研究了具有平直晶界和曲折晶界两种不同组织的GH302合金,及Rene 80合金在空气、含硫环境中的高温蠕变及断裂行为。试验结果表明,具有曲折晶界的GH302合金试样,虽然在空气环境中蠕变和持久性能明显地高于通常平直晶界试样,但在10％SO_2-空气环境中,二者的性能皆剧烈下降;定向凝固Rene80合金不仅在空气环境中性能显著优于普通铸造的合金,在含硫环境中仍保持原先水平。在含硫环境中蠕变与腐蚀的交互作用下,蠕变裂纹的扩展是以硫化-氧化腐蚀在应力促进下沿晶侵入并形成低熔点共晶,导致早期破坏。
关键词:
高温合金
,
grain boundary
,
sulphidation
,
oxidation
,
creep rupture
ZHANG Yuanhu SUN Jian XIANG Yi HU Gengxiang Shanghai Jiaotong University
,
Shanghai
,
ChinaLI Tiefan Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China Yuanhu
,
Department of Materials Science and Engineering
,
Shanghai Jiaotong University
,
Shanghai
,
200030
金属学报(英文版)
Studies on the high temperature creep and fracture behaviours in air or in SO_2 contaminated environment for the Fe-base superalloy GH302 with flat or zigzag grain boundaries(GB) and the Ni-base superalloy Rene 80 were carried out.Although the creep rupture properties of the GH302 with zigzag GB was remarkably superior to that of flat GB in air,the properties of both droped dramatically in 10% SO_2-air environment,the creep rupture properties of the directional solidified Rene 80 were much better than that of the conventionally cast alloy in air,and also kept the same property in SO_2 contaminated environment as in air.Owing to the interaction between creep and sulphidation,the failure mechanism relates to the formation of molten Ni-Ni-3S_2 eutectic along GB,led to the premature failure of the alloy.
关键词:
superalloy
,
null
,
null
,
null
,
null
F.Gesmundo F.Viani Instituto di Chimica
,
Facolta di Ingegneria
,
Universita di Genova
,
Genova
,
16129
,
ItalyY.NIU Corrosion Science Lab.
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
110015
,
China
材料科学技术（英文）
The corrosion of alloys based on Fe,Co and Ni containing 15 and 30 wt-% Nb was studied at 700℃ in H_2-H_2S mixtures providing 10~(-8) atm S_2.The Fe and Co-based alloys formed duplex scales with an outer layer of pure base-metal sulphide and an inner layer containing both metals.The Nb addi- tions were not able to produce exclusive Nb sulphidation but yielded a significant decrease of the corrosion rates for both types of alloys with respect to the pure metals even though they were still much higher than that of pure Nb.The Ni-base alloys corroded rapidly forming a single complex scale layer,mainly due to the appearance of a liquid Ni-S solution.
关键词:
niobium
,
null
,
null
,
null
