Revealing effect of Al content on oxidation of novel Co-Cr-Nb-W carbide-strengthened superalloy  

作　　者：Chen Ling Shang-Ping Li Jie Hou He-Li Luo 

机构地区：[1]Central Iron&Steel Research Institute,Beijing 100081,China [2]Beijing GAONA Materials&Technology Co.,Ltd.,Beijing 100081,China

出　　处：《Rare Metals》2024年第9期4521-4534,共14页稀有金属（英文版）

基　　金：supported by the National Key R&D Program of China(No.2022YFC3902002)。

摘　　要：The high-temperature oxidation behavior of novel Co-Cr-Nb-W carbide-strengthened wear-resistance alloys with different Al contents(1wt%,2wt%and 3wt%)at 950,1000 and 1050℃was thoroughly investigated by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy and field emission electron probe analyzer.The porous property of NbC in-situ oxidation products(Nb_(2)O_(5),Co Nb_(2)O_(6)and Co_(4)Nb_(2)O_(9))induces a multi-layered oxide scale with micropores and cracks.Co-Cr-Nb-W alloy with 1 wt%Al undergoes catastrophic oxidation and spalling above 1000℃.The outward transportation of Cr and Co is effectively restrained by a continuous Al_(2)O_(3)scale formed around NbC in-situ oxidation region when Al content reaches 3 wt%.The β-Co Al in Co-Cr-Nb-W alloy with 3 wt%Al has an oxidation priority over eutectic carbides and the alloy matrix which are both enriched with Cr,thereby preventing the formation of Cr-depletion area and improving the self-healing ability of the oxide film.A slight change in Al content has a remarkable influence on the cooperative effect of Al and Cr and multiplies the antioxidant capacity of Co-Cr-Nb-W alloy above 1000℃.

关 键 词：High-temperature oxidation behavior Oxidation kinetics SUPERALLOY Wear-resistant alloy Microstructure 

分 类 号：TG132.3[一般工业技术—材料科学与工程]