碳热还原法短流程回收废弃690合金  

Short Process Recovery of Scrap 690 Alloy by Carbon Thermal Reduction

作　　者：凌世杰 王曼[1,2] 席晓丽[1,3] Ling Shijie;Wang Man;Xi Xiaoli(National Engineering Laboratory for Industrial Big-Data Application Technology,Bejing University of Technology,Beijing 100124,China;Collaborative Innovation Center of Capital Resource-Recycling Material Technology,Faculty of Materials and Manufacturing,Bejing University of Technology,Bejing 100124,China;Key Laboratory of Advanced Functional Materials,Ministry of Education,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学材料与制造学部新型功能材料教育部重点实验室,北京100124 [2]北京工业大学首都资源循环材料技术省部共建协同创新中心,北京100124 [3]北京工业大学工业大数据应用技术国家工程实验室,北京100124

出　　处：《稀有金属》2024年第10期1426-1435,共10页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(52025042)资助。

摘　　要：废弃镍基合金的循环利用可有效缓解中国镍矿对外依存度高的现状。然而,废弃镍基合金中存在大量夹杂相,造成重熔合金性能降低,无法满足使用要求。针对上述问题,以废弃690合金为原料,利用真空感应熔炼炉在1550℃下采用碳热还原法去除氧化物夹杂相以制备高性能重熔690合金。使用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)分析了废弃690合金、直接重熔690合金和加碳重熔690合金的微观组织,使用维氏显微硬度仪和电子万能试验机对3种合金进行力学性能检测。结果表明,碳热还原法可以将Cr_(2)O_(3)夹杂相转变为Cr_(23)C_(6)析出相,有效去除了废弃690合金中的Cr_(2)O_(3)。大量均匀分布的Cr_(23)C_(6)析出相不仅可起到弥散强化作用,还有利于形成细晶组织提高细晶强化效果,使加碳重熔690合金力学性能大幅提升。与直接重熔690合金相比,加碳重熔690合金室温延伸率、高温延伸率分别提高了18.8%和96.0%;与标准690合金相比,其室温延伸率、高温延伸率分别提升了14.3%和32.5%。Nickel is an important raw material for fabrication of high-temperature alloys and corrosion-resistant alloys due to its high melting point,corrosion resistance,oxidation resistance,ductility and other excellent properties.As one kind of key strategic resources,nickel has been widely used in aerospace,defense,nuclear energy and other important fields.However,China is a typical nickel-deficit country,and the dependence on foreign nickel ore reaches as high as 95%.Recycling of nickel-contained scrap can effectively alleviate the shortage of nickel resources,and is of great significance to ensure the safe and sustainable supply of nickel resources in China.Compared with other types of nickel-contained scraps,nickel-based high-temperature alloy scrap exhibits higher recovery value because of its advanced preparation process and containing various kinds of strategic metal elements.Currently,different methods including pyrometallurgical,hydrometallurgical,and pyro-hydrometallurgical processing are applied for recycling scrap nickel-based hightemperature alloys.However,these methods have disadvantages such as multi-step processing and relatively low utilization rates.What′s more,the achieved products by the above methods usually are metal elements or corresponded salts.To achieve same-level utilization of scrap nickel-based alloys,a direct re-melting method through vacuum induction melting is used to recycle scrap 690 alloy.However,re-melted 690 alloy shows poor performance,especially deterioration of ductility,which is resulted from a large number of Cr_(2)O_(3)inclusions distrusted in re-melted 690 alloy.Consequently,Cr_(2)O_(3)inclusions cannot be removed effectively through the direct re-melting method.Therefore,carbon thermal reduction was proposed to solve this problem in this study.Scrap 690 alloy was obtained through aging treatment at 850℃for 360 h by considering that oxidation as well as microstructure coarsening were the main factors for serving failure of690 alloys.The above scrap 690 alloy were re-melte

关 键 词：废弃690合金 碳热还原 循环利用 短流程 高性能 

分 类 号：TG146[一般工业技术—材料科学与工程]