文章信息/Info

Title:

Effect of Micro-Grain Casting Process on Microstructure and Stress Rupture Properties of K4169 Alloy

文章編號:

1674-3962(2024)10-0865-06

作者:

胡聘聘; 王越; 李妍佳; 何金珊; 張麗輝; 羅亮; 王西濤; 肖程波

1.中國航發北京航空材料研究院 先進高溫結構材料重點實驗室，北京 100095 2.北京科技大學 鋼鐵共性技術協同創新中心，北京 100083 3.齊魯工業大學 山東省輕質高強金屬材料省級重點實驗室，山東 濟南 250014

Author(s):

HU Pinpin; WANG Yue; LI Yanjia; HE Jinshan; ZHANG Lihui; LUO Liang; WANG Xitao; XIAO Chengbo

1.Science and Technology on Advanced High Temperature Structural Materials Laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, China 2.Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China et al.

關鍵詞:

K4169; 細晶鑄造; 微晶鑄造; 顯微組織; 持久性能; 斷裂機制; 高溫合金

Keywords:

K4169;  fine grain casting;  micro-grain casting;  microstructure;  stress rupture property;  fracture mechanism; superalloy

分類號:

TG132.3

DOI:

10.7502/j.issn.1674-3962.202308030

文獻標志碼:

A

摘要:

分別采用普通鑄造、細晶鑄造和微晶鑄造工藝制得了晶粒度為ASTM M9～M7級、ASTM M14～M9級和ASTM 3～5級的K4169合金試樣，研究了微晶鑄造對K4169合金組織及持久性能的影響。研究結果表明，微晶鑄造工藝可顯著細化晶粒，降低凝固偏析，減少Laves相和大塊MC碳化物，增加γ″相體積分數；使合金704 ℃/448 MPa條件下的持久性能相比于普通鑄造和細晶鑄造合金分別提高了621%和44%，達到614.9 h；斷裂模式從普通鑄造K4169的脆性穿晶斷裂轉變為微晶鑄造K4169的韌性沿晶穿晶混合型斷裂。微晶鑄造工藝引起的晶粒細化和γ″相體積分數的提高，有效強化了K4169合金，而大塊MC碳化物及Laves相的減少，減少了潛在的裂紋萌生、擴展位置，二者共同作用提高了K4169合金的持久壽命，并降低了性能數據分散性。微晶鑄造工藝可獲得良好的綜合力學性能，提升K4169合金機匣、殼體、擴壓器等整體結構件在700 ℃以下的服役性能，有良好的應用前景。

Abstract:

K4169 samples with grain size of ASTM M9～M7, ASTM M14~M9 and ASTM 3~5 were prepared by conventional casting process, fine grain casting process and micro-grain casting process, respectively. The effects of micro-grain casting process on the microstructures and stress rupture properties of K4169 alloy were analyzed. Results show that micro-grain casting process can significantly refine grains, reduce solidification segregation and the content of Laves phase and large bulk MC carbides, increase the volume fraction of γ″ phase, thus improve the mechanical properties of K4169 alloy. The stress rupture life at 704 ℃/448 MPa of micro-grain K4169 alloy is up to 614.9 h, which is 621% and 44% higher than that of conventional K4169 and fine�瞘rain K4169, respectively. The fracture mode transforms from brittle transgranular fracture of conventional K4169 to ductile mixed�瞞ode fracture (transgranular fracture and intergranular fracture) of micro-grain K4169. Grain refinement and the increased volume fraction of γ″ effectively strengthen K4169 alloy, while the decreases of Laves phase and large bulk MC carbides reduce the potential crack initiation and propagation locations. The combination of the above two points improves the stress rupture life of K4169 alloy and reduces the dispersion of performance data. The micro-grain casting process can obtain good comprehensive mechanical properties and improve the service performance of K4169 alloy below 700 ℃, which has a good application prospect.