Zhongfeng Chen , Anping Dong , Zhengye Zhang , Lin He , Dafan Du , Lianghua Xiong , Yunwei Pan
{"title":"800℃NaCl盐雾腐蚀对niccr基高温合金断裂行为及变形机制的影响","authors":"Zhongfeng Chen , Anping Dong , Zhengye Zhang , Lin He , Dafan Du , Lianghua Xiong , Yunwei Pan","doi":"10.1016/j.intermet.2025.109013","DOIUrl":null,"url":null,"abstract":"<div><div>NiCoCr-based superalloys operating in marine environments are subjected to severe corrosion, which can significantly affect their mechanical performance. In this study, a systematic investigation is carried out to elucidate the effects of NaCl salt-spray exposure at 800 °C on fracture behavior and deformation mechanisms of a newly developed γ′-strengthened NiCoCr-based superalloy, K439B. The tensile tests reveal a degradation of mechanical performance after NaCl salt-spray exposure at 800 °C for 70 h: the ultimate tensile strength (UTS) decreases from 1113 MPa to 816 MPa, and the elongation at break (EL) drops from 6.0 % to 1.2 %. Fracture morphologies show that the uncorroded specimen exhibits mixed ductile-brittle fracture features with quasi-cleavage facets, ductile dimples, and slip-band evidence, whereas the corroded specimen develops a corrosion-affected zone at the fracture edge, containing a high density of corrosion-induced voids. These voids are considered as crack initiation sites and stress concentrators, promoting brittle failure. Elemental distribution within the corrosion-affected zone reveals the depletion of Cr and γ′-forming elements (<em>e.g.</em>, Al, Ti), and the local stress concentrations adjacent to corrosion voids are observed. In addition, the uncorroded specimen deforms primarily by planar slip and stacking fault cutting γ′ phase, while the corroded specimen shows dense dislocation tangling around corrosion voids and pile-up at the grain boundary and around the Al oxides, leading to the significant decrease in ductility. The results show mechanical degradation and altered deformation mechanisms in K439B alloy after NaCl salt-spray exposure at 800 °C, offering critical insights for evaluating its service performance in high-temperature marine environments.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"187 ","pages":"Article 109013"},"PeriodicalIF":4.8000,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effects of 800°C NaCl salt-spray corrosion on fracture behavior and deformation mechanism in a NiCoCr-based superalloy\",\"authors\":\"Zhongfeng Chen , Anping Dong , Zhengye Zhang , Lin He , Dafan Du , Lianghua Xiong , Yunwei Pan\",\"doi\":\"10.1016/j.intermet.2025.109013\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>NiCoCr-based superalloys operating in marine environments are subjected to severe corrosion, which can significantly affect their mechanical performance. In this study, a systematic investigation is carried out to elucidate the effects of NaCl salt-spray exposure at 800 °C on fracture behavior and deformation mechanisms of a newly developed γ′-strengthened NiCoCr-based superalloy, K439B. The tensile tests reveal a degradation of mechanical performance after NaCl salt-spray exposure at 800 °C for 70 h: the ultimate tensile strength (UTS) decreases from 1113 MPa to 816 MPa, and the elongation at break (EL) drops from 6.0 % to 1.2 %. Fracture morphologies show that the uncorroded specimen exhibits mixed ductile-brittle fracture features with quasi-cleavage facets, ductile dimples, and slip-band evidence, whereas the corroded specimen develops a corrosion-affected zone at the fracture edge, containing a high density of corrosion-induced voids. These voids are considered as crack initiation sites and stress concentrators, promoting brittle failure. Elemental distribution within the corrosion-affected zone reveals the depletion of Cr and γ′-forming elements (<em>e.g.</em>, Al, Ti), and the local stress concentrations adjacent to corrosion voids are observed. In addition, the uncorroded specimen deforms primarily by planar slip and stacking fault cutting γ′ phase, while the corroded specimen shows dense dislocation tangling around corrosion voids and pile-up at the grain boundary and around the Al oxides, leading to the significant decrease in ductility. The results show mechanical degradation and altered deformation mechanisms in K439B alloy after NaCl salt-spray exposure at 800 °C, offering critical insights for evaluating its service performance in high-temperature marine environments.</div></div>\",\"PeriodicalId\":331,\"journal\":{\"name\":\"Intermetallics\",\"volume\":\"187 \",\"pages\":\"Article 109013\"},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2025-09-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Intermetallics\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0966979525003784\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Intermetallics","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0966979525003784","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Effects of 800°C NaCl salt-spray corrosion on fracture behavior and deformation mechanism in a NiCoCr-based superalloy
NiCoCr-based superalloys operating in marine environments are subjected to severe corrosion, which can significantly affect their mechanical performance. In this study, a systematic investigation is carried out to elucidate the effects of NaCl salt-spray exposure at 800 °C on fracture behavior and deformation mechanisms of a newly developed γ′-strengthened NiCoCr-based superalloy, K439B. The tensile tests reveal a degradation of mechanical performance after NaCl salt-spray exposure at 800 °C for 70 h: the ultimate tensile strength (UTS) decreases from 1113 MPa to 816 MPa, and the elongation at break (EL) drops from 6.0 % to 1.2 %. Fracture morphologies show that the uncorroded specimen exhibits mixed ductile-brittle fracture features with quasi-cleavage facets, ductile dimples, and slip-band evidence, whereas the corroded specimen develops a corrosion-affected zone at the fracture edge, containing a high density of corrosion-induced voids. These voids are considered as crack initiation sites and stress concentrators, promoting brittle failure. Elemental distribution within the corrosion-affected zone reveals the depletion of Cr and γ′-forming elements (e.g., Al, Ti), and the local stress concentrations adjacent to corrosion voids are observed. In addition, the uncorroded specimen deforms primarily by planar slip and stacking fault cutting γ′ phase, while the corroded specimen shows dense dislocation tangling around corrosion voids and pile-up at the grain boundary and around the Al oxides, leading to the significant decrease in ductility. The results show mechanical degradation and altered deformation mechanisms in K439B alloy after NaCl salt-spray exposure at 800 °C, offering critical insights for evaluating its service performance in high-temperature marine environments.
期刊介绍:
This journal is a platform for publishing innovative research and overviews for advancing our understanding of the structure, property, and functionality of complex metallic alloys, including intermetallics, metallic glasses, and high entropy alloys.
The journal reports the science and engineering of metallic materials in the following aspects:
Theories and experiments which address the relationship between property and structure in all length scales.
Physical modeling and numerical simulations which provide a comprehensive understanding of experimental observations.
Stimulated methodologies to characterize the structure and chemistry of materials that correlate the properties.
Technological applications resulting from the understanding of property-structure relationship in materials.
Novel and cutting-edge results warranting rapid communication.
The journal also publishes special issues on selected topics and overviews by invitation only.