熱均壓及添加鈷元素對CM-681LC鎳基超合金超高溫潛變性質之影響

Effect of Hot Isostatic Pressure and Addition of Cobalt Element on High-Temperature Creep of CM-681LC Ni-Base Superalloy

鄭名翃(Ming-Hong Jheng)

指導教授 ： 簡賸瑞

共同指導教授 ： 郭振明(Chen-Ming Kuo)

義守大學/理工學院/材料科學與工程學系/碩士(2018年)

摘要

本研究採用CM-681LC鎳基超合金作為母材，進行單方向凝固鑄造，藉由微量添加鈷元素含量(+3%)及熱均壓製程，探討其微觀組織之差異性及高溫潛變的變化與影響。實驗過程首先利用真空感應熔煉爐製成實驗所需單方向凝固鑄造試棒，經過三階段熱處理程序(固溶處理1270℃/4hr/ArC，一次時效1038℃/2hr/ArC和二次時效870℃/20hr/ArC)，再進行超高溫潛變(1050℃/200MPa)實驗。另外探討提高鈷元素比例及/或經過熱均壓製程後是否能增加超高溫潛變的壽命，並探討微觀組織之差異性。分析實驗以X-ray繞射分析儀進行材料相鑑定、掃描式電子顯微鏡及穿透式電子顯微鏡進行微觀組織觀察。研究結果顯示，熱均壓製程或添加鈷元素後並不會提升單方向凝固CM-681LC鎳基超合金的超高溫潛變壽命；但是，熱均壓製程卻能提升添加鈷元素後的單方向凝固CM-681LC鎳基超合金超高溫潛變壽命。

關鍵字

CM-681 LC鎳基超合金 ； 微觀組織 ； 高溫潛變

並列摘要

In this study, CM-681LC nickel-base superalloy was used as the base material to investigate the difference of microstructure and the influence of high temperature creep behavior by Cobalt element addition (+3%) and hot isostatic pressure process. Experimental procedure firstly uses the vacuum induction melting furnace to make the directionally solidified specimens, three-stage heat treatments (solution treatment at 1270°C/4hr/ArC, primary aging at 1038°C/2hr/ArC and secondary aging at 870°C/20hr/ArC), and then ultra-high temperature creep (1050°C/200MPa) experiment. In addition, by increasing the cobalt content and/or performing the hot isostatic pressure process to improve the ultra-high temperature creep life were investigated, and the differences of microstructure were discussed. Analytical experiments employ X-ray diffraction analyzer to identify phases, scanning electron microscope and transmission electron microscope to observe the microstructures. Results show that the hot isostatic pressure process and/or the addition of cobalt element do not improve the ultra-high temperature creep life of directionally solidified CM-681LC nickel-based superalloy; however, the hot isostatic pressure process can enhance the ultra-high temperature creep life of directionally solidified CM-681LC nickel base superalloy with cobalt addition.

並列關鍵字

CM-681LC nickel-based superalloy ； microstructure ； high-temperature creep

參考文獻

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