东北大学学报(自然科学版) ›› 2013, Vol. 34 ›› Issue (11): 1580-1584.DOI: 10.12068/j.issn.1005-3026.2013.11.015

• 材料与冶金 • 上一篇    下一篇

定向凝固镍基DZ792及DZ792G合金的高温热腐蚀行为

黄烁1,王磊1,黄炎1,李俊涛2   

  1. (1东北大学 材料各向异性与织构教育部重点实验室,辽宁沈阳110819;2北京钢铁研究总院高温材料研究所,北京100081)
  • 发布日期:2013-07-09
  • 通讯作者: 黄烁
  • 作者简介:黄烁(1988-),男,河北沧州人,东北大学博士研究生;王磊(1961-),男,河北唐山人,东北大学教授,博士生导师.
  • 基金资助:
    国家重点基础研究发展计划项目(2010CB631203);国家自然科学基金资助项目(51171039).

High Temperature Hot Corrosion Behaviors of Directional Solidification NiBase Superalloy DZ792 and DZ729G〓

HUANG Shuo1, WANG Lei1, HUANG Yan1, LI Juntao2   

  1. 1. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China; 2. Institute of High Temperature Materials, Central Iron & Steel Research Institute, Beijing 100081, China.
  • Published:2013-07-09
  • Contact: WANG Lei
  • About author:-
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摘要: 采用涂盐法研究了DZ792与DZ792G合金涂覆75%Na2SO4+25%NaCl混合盐后在900℃下的热腐蚀行为与机理.结果表明,900℃涂盐腐蚀条件下DZ792与DZ792G合金的热腐蚀机制为“酸/碱盐溶-内硫化氧化”.DZ792G合金在热腐蚀70~150h,腐蚀机制由碱性盐溶机制转化为酸性盐溶机制,最终导致灾难性腐蚀.DZ792G合金因具有较高的Ti含量,合金表面氧化膜的外侧形成富Ti氧化物层,TiO2与熔盐反应消耗其中的O2-,促进热腐蚀由碱性向酸性盐溶机制转变.而DZ792合金Ti含量较低,TiO2层在氧化膜内侧形成,外侧少量Ti氧化物形成稳定的NiTiO3尖晶石层.DZ792合金氧化膜外侧的富Cr2O3层与熔盐直接反应,抑制了热腐蚀反应,因而具有优异的抗热腐蚀能力.

关键词: 定向凝固镍基高温合金, DZ792, 盐膜, 混合盐, 热腐蚀行为

Abstract: The hot corrosion behaviors and mechanisms of DZ792 and DZ792G alloys at 900℃ through 75%Na2SO4+25% NaCl salt deposit were investigated. The results showed that the hot corrosion mechanisms of DZ792 and DZ792G alloys under 900℃ salt deposit were “acidicalkali dissolution/inter sulfideoxide”. During the hot corrosion testing between 70h and 150h, the corrosion mechanism of DZ792G alloy changed from alkali to acidic dissolution mechanism, finally resulting in the catastrophic corrosion for DZ792G alloy, the O2 in molten salt preferentially reacted with the outside Tirich layer at the surface of DZ792 alloy rather than that with inner Cr2O3 layer owing to the high Ti content of this alloy, thus, the mechanism of the hot corrosion changed from alkali to acidic dissolution with the TiO2 reacted with the molten salt consuming the O2. However, because the Ti content of DZ792 alloy was lower than that of DZ792G, the Tirich layer formed in the middle of the multilayered oxide, and the outer Tirich oxide formed stable spinel NiTiO3. The outer Cr2O3 rich oxide layer of the DZ792 reacted with the salt directly, therefore, the further corrosion of DZ792 alloy enable to be inhibited.

Key words: directional solidification Nibase alloys, DZ792, salt deposit, salt mixture, hot corrosion behaviours

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