文章信息/Info

Title:

Material and Processing Technology of Directionally Solidified Blade in Heavy Duty Industrial Gas Turbines

作者:

張健; 樓瑯洪; 李輝

（中國科學院金屬研究所，遼寧 沈陽 110016）

Author(s):

ZHANG Jian;  LOU Langhong;  LI Hui

(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)

關鍵詞:

重型燃氣輪機; 定向結晶葉片; 材料與工藝

DOI:

10.7502/j.issn.1674-3962.2013.01.02

摘要:

重型燃氣輪機是我國能源發展戰略中的關鍵裝備。在高溫和熱腐蝕環境下工作的透平葉片，是重型燃機的核心熱端部件。與航空發動機葉片比較，先進重型燃氣輪機透平葉片，在高溫熱腐蝕環境下長期工作，而且葉片的尺寸較大，因此，對葉片使用的高溫合金材料及其制造工藝均提出了特殊的要求。用于燃氣輪機葉片的抗熱腐蝕高溫合金材料，經歷了從多晶到定向和單晶的發展歷程，其合金在設計中具有高Cr，高Ti，Al比等幾個顯著區別于航空發動機葉片材料的特征。兼顧高強度、優異抗熱腐蝕性能及長期組織和性能穩定性的燃氣輪機用鑄造高溫合金的研發，因此更具挑戰。定向凝固是重型燃氣輪機用大型定向結晶葉片制造工藝中最為關鍵的技術之一。介紹了先進定向凝固技術——高溫度梯度液態金屬冷卻定向凝固技術的發展，對比了不同定向凝固工藝對高溫合金典型組織及力學性能的影響，并簡單介紹了我國近期在大型定向結晶葉片研制方面的進展。

Abstract:

Turbine blades used in heavy duty industrial gas turbines (IGT) serve at high temperatures and in an aggressive environment. The present paper gives an overview of the materials and processing techniques of IGT blades. Comparing to the turbine blades used in aero engines, IGT blades operate at high temperature, hot corrosion environment for longer time, and are with much larger size. The principles of material design and manufacture of these large blades are therefore required with special considerations. The temperature capability of materials used as IGT blade is increasing over the past decades due to the development of directionally solidified (DS) and single crystal superalloys. Features such as high Cr content and Ti/Al ratio are unique in these alloys comparing to the alloys used in aero engines. Consequently, development of alloys with high strength, high hot corrosion resistance, as well as good long term stabilities is a very challenged task. Directional solidification is one of the most important techniques in manufacturing the large blade. The development of advanced high gradient DS process�瞝iquid metal cooling process has been described. Typical microstructure and properties of superalloys processed by different DS techniques are compared. Some recent progresses in manufacturing the large blades in China have also been depicted.