文章信息/Info

Title:

The Influence of Carbon Contents on the Microstructure and Tensile Properties of a Ni-Based Single Crystal Superalloy

文章編號(hào):

1674-3962(2025)11-1027-08

作者:

陶巖; 李永梅; 譚子昊; 曹亮; 王新廣

1.遼寧石油化工大學(xué)機(jī)械工程學(xué)院，遼寧 撫順 113001 2.中國科學(xué)院金屬研究所，遼寧 沈陽 110006

Author(s):

Tao Yan; Li Yongmei; Tan Zihao; Cao Liang; Wang Xinguang

1. School of Mechanical Engineering，Liaoning Petrochemical University，F(xiàn)ushun 113001，China 2. Institute of Metal and Research，Chinese Academy of Science，Shenyang 110006，China

關(guān)鍵詞:

鎳基單晶高溫合金; 渦輪葉片; 拉伸強(qiáng)度; 碳化物; 定向凝固

Keywords:

Ni-based single crystal superalloy;  turbine blades;  tensile strength;  carbides;  directional solidification

分類號(hào):

TG132.3;V232.4;V252

DOI:

10.7502/j.issn.1674-3962.202407023

文獻(xiàn)標(biāo)志碼:

A

摘要:

研究了C元素對(duì)一種低成本第二代鎳基單晶高溫合金微觀組織與拉伸變形行為的影響。結(jié)果表明，隨著C含量增加，鑄態(tài)合金枝晶間的共晶組織逐漸消失，MC型碳化物含量升高，而經(jīng)標(biāo)準(zhǔn)熱處理后，不同C含量合金的γ+γ′兩相組織均無明顯變化。當(dāng)拉伸溫度為800和1100 ℃時(shí)，C含量增加均導(dǎo)致合金的拉伸強(qiáng)度與塑性降低。盡管合金在高溫拉伸變形中析出的顆粒狀M6C型碳化物與γ′相為共格析出關(guān)系，有助于阻礙超位錯(cuò)切割γ′相，但位于枝晶間的MC型碳化物又將消耗大量Ta，W等難熔元素，進(jìn)而削弱了基體的固溶強(qiáng)化效果，最終導(dǎo)致合金拉伸強(qiáng)度降低。此外，枝晶間骨架狀MC型碳化物的存在促進(jìn)了800 ℃拉伸時(shí)合金沿碳化物生長平面的解理斷裂，并加速了合金在1100 ℃拉伸時(shí)的裂紋萌生與擴(kuò)展，是合金塑性降低的主要原因。

Abstract:

The effect of carbon content on the microstructure, tensile properties and deformation behavior of a low-cost second-generation Ni-based single crystal superalloy was investigated. The results showed that the area fraction of eutectic microstructure in the interdendritic region decreased with the increase of carbon content, while the content of MC-type carbides increased correspondingly. After standard heat treatment, no significant difference was observed in γ+γ′ microstructure among alloys with varying carbon contents. For tensile properties at high temperature, the increase of carbon content led to a decrease in tensile strength and plasticity at both 800 and 1100 ℃. Although the blocky M6C-type carbides coherently precipitated from the matrix during the tensile deformation, which helped to hinder superdislocation cutting into the γ′. The precipitation MC carbides located in the interdendritic regions would consume a large number of refractory elements like Ta and W, which substantially weakened the solid solution strengthening effect of γ matrix,resulting in a reduction of tensile strength. The interdendritic skeleton�瞝ike MC carbides promoted the cleavage fracture along the carbides at 800 ℃ tension, and accelerated the micro-crack initiation and macro-crack extensionat 1100 ℃ tension, which were considered as the main reason for the decrease in the alloy‘’s plasticity.