{"title":"Effect of microstructure evolution on mechanical properties and oxidation behavior of Super304H and HR3C after long-term service","authors":"Lei Zhao, Xinyu Li, Lianyong Xu, Yongdian Han, Kangda Hao, Xiangfeng Zheng","doi":"10.1007/s10853-024-10230-5","DOIUrl":null,"url":null,"abstract":"<div><p>The oxidation structure, microstructure and mechanical properties of Super304H and HR3C are investigated after running at 630 °C/3 MPa for 40,000 h. After service, a duplex oxide is formed on the steam side of heat-resistant steel, and it is possible that the surface treatment has caused surface deformation of Super304H, leading to an increase in corrosion resistance. For Super304H, a chain-like distribution of M<sub>23</sub>C<sub>6</sub> has been formed at the grain boundaries, causing creep cavities, NbCrN and <i>ɛ</i>-Cu particles have precipitated inside the grains. For HR3C, there is a significant aggregation of Cr at the grain boundaries, with only a small amount of M<sub>23</sub>C<sub>6</sub> and <i>σ</i> phase, and a large number of nanoscale NbCrN particles appear within the grains. The stable and dispersed precipitates inside the grains hinder the movement of dislocations, allowing heat-resistant steel to maintain higher strength than its as-received condition after long-term service. The microstructure evolution at grain boundaries leads to a decrease in toughness and plasticity of heat-resistant steel, and the continuous evaporation of Cr in high-temperature steam will cause a gradual decrease in Cr concentration and a deterioration in oxidation resistance of heat-resistant steel.</p></div>","PeriodicalId":645,"journal":{"name":"Journal of Materials Science","volume":"59 48","pages":"22206 - 22227"},"PeriodicalIF":3.5000,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Materials Science","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s10853-024-10230-5","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The oxidation structure, microstructure and mechanical properties of Super304H and HR3C are investigated after running at 630 °C/3 MPa for 40,000 h. After service, a duplex oxide is formed on the steam side of heat-resistant steel, and it is possible that the surface treatment has caused surface deformation of Super304H, leading to an increase in corrosion resistance. For Super304H, a chain-like distribution of M23C6 has been formed at the grain boundaries, causing creep cavities, NbCrN and ɛ-Cu particles have precipitated inside the grains. For HR3C, there is a significant aggregation of Cr at the grain boundaries, with only a small amount of M23C6 and σ phase, and a large number of nanoscale NbCrN particles appear within the grains. The stable and dispersed precipitates inside the grains hinder the movement of dislocations, allowing heat-resistant steel to maintain higher strength than its as-received condition after long-term service. The microstructure evolution at grain boundaries leads to a decrease in toughness and plasticity of heat-resistant steel, and the continuous evaporation of Cr in high-temperature steam will cause a gradual decrease in Cr concentration and a deterioration in oxidation resistance of heat-resistant steel.
期刊介绍:
The Journal of Materials Science publishes reviews, full-length papers, and short Communications recording original research results on, or techniques for studying the relationship between structure, properties, and uses of materials. The subjects are seen from international and interdisciplinary perspectives covering areas including metals, ceramics, glasses, polymers, electrical materials, composite materials, fibers, nanostructured materials, nanocomposites, and biological and biomedical materials. The Journal of Materials Science is now firmly established as the leading source of primary communication for scientists investigating the structure and properties of all engineering materials.