Incoloy 800H銲件在950℃乾空氣環境之循環氧化行為研究

The Cyclic Oxidation Behavior of Welded Inconel 800H Superalloy at 950 °C in Dry Air

鄭福本(F. B. Zheng) ； 陳偉昇(W. S. Chen) ； 宋建群(C. C. Sung) ； 開物(W. Kai) ； 開執中(J. J. Kai)

《防蝕工程》 29卷2期 (2015/06) Pp. 89-96

https://doi.org/10.6376/JCCE.201506_29(2).0005

摘要

本研究探討Incoloy 800H 經銲接處理後之基材(800H-SUB)、熱影響區(800H-HAZ)及銲道(800H-MZ)三種區域在950 °C 乾空氣下的循環氧化行為。研究結果顯示，合金經20 次循環之氧化速率由快而慢依序為800H-HAZ ＞ 800H-SUB ＞ 800H-MZ。由SEM 及XRD 分析得知，氧化後三種區域皆生成兩層氧化層，其中，800H-SUB 與800H-HAZ 兩者內層主要生成Cr_2O_3 及(Fe,Cr)_2O_4，外層主要生成Fe_2O_3 和Fe_3O_4；然而800H-MZ 氧化後外層生成MnCr_2O_4 及(Ni,Cr)_3O_4，內層氧化層則為Cr_2O_3；推測母材中Mn 離子的外擴散所形成MnCr_2O_4是800H-MZ 合金氧化速率較慢的主因。

關鍵字

鎳基超合金 ； 氧化動力學

並列摘要

The cyclic oxidation behavior of three different zones of welded Incoloy 800H, containing the substrate (800H-SUB), the heat-affected zone (800H-HAZ) and the melt zone (800H-MZ), was studied at 950 °C in dry air. The results showed that the oxidation-resistant ability of the alloys after the 20-cycle followed by the rank from fast to slow of 800H-HAZ ＞ 800H-SUB ＞ 800H-MZ. The scales formed on the 800H-SUB and 800H-HAZ consisted of a heterophasic mixture of Cr_2O_3 and FeCr_2O_4 in the inner layer, as well as Fe_2O_3 and Fe_3O_4 in the outer layer. Duplex scales also formed on 800H-MZ consisted of an outer layer of MnCr_2O_4 and small amount of (Ni,Cr)_3O_4, and an inner layer of Cr_2O_3. The MnCr_2O_4 formation by Mn ion outer diffusion was responsible for the slow oxidation rate of 800H-MZ.

並列關鍵字

Ni-based superalloys ； Oxidation kinetics ； Cr_2O_3 ； MnCr_2O_4 ； Fe_2O_3/Fe_3O_4