{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T04:23:09Z","timestamp":1790223789966,"version":"4.1.0"},"reference-count":25,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T00:00:00Z","timestamp":1656979200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Korea Institute of Energy Technology Evaluation and Planning (KETEP)","award":["20217410100050"],"award-info":[{"award-number":["20217410100050"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>HR3C (25Cr-20Ni-Nb-N) is a key material used in heat exchangers in supercritical power plants. Its creep properties and microstructural evolution has been extensively studied at or below 650 \u00b0C. The precipitation evolution in HR3C steel after creep rupture at elevated temperatures of 700 \u00b0C and 750 \u00b0C with a stress range of 70~180 MPa is characterized in this paper. The threshold strength at 700 \u00b0C and 750 \u00b0C were determined by extrapolation method to be \u03c3105700= 57.1 MPa and \u03c3105750=37.5 MPa, respectively. A corresponding microstructure investigation indicated that the main precipitates precipitated during creep exposure are Z-phase (NbCrN), M23C6, and \u03c3 phase. The dense Z-phase precipitated dispersively in the austenite matrix along dislocation lines, and remained stable (both size and fraction) during long-term creep exposure. M23C6 preferentially precipitated at grain boundaries, and coarsening was observed in all creep specimens with some continuous precipitation of granular M23C6 in the matrix. The brittle \u03c3 phase formed during a relatively long-term creep, whose size and fraction increased significantly at high temperature. Moreover, the \u03c3 phases, grown and connected to form a large \u201cisland\u201d at triple junctions of grain boundaries, appear to serve as nucleation sites for high stress concentration and creep cavities, weakening the grain boundary strength and increasing the sensitivity to intergranular fracture.<\/jats:p>","DOI":"10.3390\/ma15134704","type":"journal-article","created":{"date-parts":[[2022,7,6]],"date-time":"2022-07-06T05:41:06Z","timestamp":1657086066000},"page":"4704","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Precipitation Evolution in the Austenitic Heat-Resistant Steel HR3C upon Creep at 700 \u00b0C and 750 \u00b0C"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9630-6271","authenticated-orcid":false,"given":"Liming","family":"Xu","sequence":"first","affiliation":[{"name":"School of Materials Science and Engineering, Changwon National University, Changwon 51140, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yinsheng","family":"He","sequence":"additional","affiliation":[{"name":"KEPCO Research Institute, Korea Electric Power Corporation, Daejeon 34056, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yeonkwan","family":"Kang","sequence":"additional","affiliation":[{"name":"KEPCO Research Institute, Korea Electric Power Corporation, Daejeon 34056, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jine-sung","family":"Jung","sequence":"additional","affiliation":[{"name":"KEPCO Research Institute, Korea Electric Power Corporation, Daejeon 34056, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keesam","family":"Shin","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, Changwon National University, Changwon 51140, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,5]]},"reference":[{"key":"ref_1","first-page":"195","article-title":"Heat-resistant steels, microstructure evolution and life assessment in power plants","volume":"10","author":"Hu","year":"2012","journal-title":"Therm. Power Plants"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/S1006-706X(13)60082-5","article-title":"Effect of aging at 700 \u00b0C on microstructure and mechanical properties of S31042 heat resistant steel","volume":"20","author":"Wang","year":"2013","journal-title":"J. Iron Steel Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1448","DOI":"10.1016\/j.jmst.2017.01.025","article-title":"Precipitation and hot deformation behavior of austenitic heat-resistant steels: A review","volume":"33","author":"Zhou","year":"2017","journal-title":"J. Mater. Sci. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1179\/174892408X382860","article-title":"Long term creep properties and microstructure of SUPER304H, TP347HFG, and HR3C for A-USC boilers","volume":"2","author":"Iseda","year":"2007","journal-title":"Energy Mater."},{"key":"ref_5","unstructured":"Gharehbaghi, A. (2012). Precipitation Study in a High Temperature Austenitic Stainless Steel Using Low Voltage Energy dispersive X-ray Spectroscopy. [Master\u2019s Thesis, Royal Institute of Technology (KTH)]."},{"key":"ref_6","first-page":"790","article-title":"Crystal Structure of Nb Cr N","volume":"209","author":"Jack","year":"1972","journal-title":"J. Iron Steel Inst."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Gola\u0144ski, G., Zieli\u0144ski, A., Sroka, M., and S\u0142ania, J. (2020). The effect of service on microstructure and mechanical properties of HR3C heat-resistant austenitic stainless steel. Materials, 13.","DOI":"10.3390\/ma13061297"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"765","DOI":"10.1016\/S1006-706X(14)60139-4","article-title":"Microstructure evolution and mechanical properties of HR3C steel during long-term aging at high temperature","volume":"21","author":"Bin","year":"2014","journal-title":"J. Iron Steel Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/S0921-5093(01)01754-3","article-title":"The occurrence of grain boundary serration and its effect on the M23C6 carbide characteristics in an AISI 316 stainless steel","volume":"332","author":"Hong","year":"2002","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.msea.2016.10.077","article-title":"Microstructure evolution in HR3C austenitic steel during long-term creep at 650 \u00b0C","volume":"681","author":"Zhang","year":"2017","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"664","DOI":"10.1080\/18811248.2003.9715404","article-title":"Application of small punch test to evaluate sigma-phase embrittlement of pressure vessel cladding material","volume":"40","author":"Lee","year":"2003","journal-title":"J. Nucl. Sci. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.matchar.2017.03.030","article-title":"Long-term evolution of \u03c3 phase in 304H austenitic stainless steel: Experimental and computational investigation","volume":"128","author":"Ji","year":"2017","journal-title":"Mater. Charact."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2473","DOI":"10.1016\/S1359-6454(00)00069-0","article-title":"\u03c3-phase precipitation in stabilized austenitic stainless steels","volume":"48","author":"Schwind","year":"2000","journal-title":"Acta Mater."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1355","DOI":"10.1007\/s40195-019-00878-3","article-title":"Precipitation behavior of \u03c3 phase in ultra-supercritical boiler applied HR3C heat-resistant steel","volume":"32","author":"Cao","year":"2019","journal-title":"Acta Metall. Sin."},{"key":"ref_15","unstructured":"Sawada, K., Kimura, K., and Abe, F. (2022, June 28). Data Sheets on the Elevated-Temperature Properties of 25Cr\u201320Ni\u2013Nb\u2013N Stainless Steel Tube for Power Boilers (KA-SUS310J1 TB). NIMS Creep Data Sheet No. 58: National Institute for Materials Science, Available online: https:\/\/mdr.nims.go.jp\/concern\/publications\/v118rf25g."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4552","DOI":"10.1007\/s11665-021-05754-9","article-title":"Microstructure Characteristics and Their Effects on the Mechanical Properties of As-Served HR3C Heat-Resistant Steel","volume":"30","author":"Wang","year":"2021","journal-title":"J. Mater. Eng. Perform."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1515\/amm-2016-0129","article-title":"The effect of long-term impact of elevated temperature on changes in microstructure and mechanical properties of HR3C steel","volume":"61","author":"Sroka","year":"2016","journal-title":"Arch. Metall. Mater."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1016\/j.msea.2018.10.124","article-title":"Investigation the effect of precipitating characteristics on the creep behavior of HR3C austenitic steel at 650 \u00b0C","volume":"742","author":"Hu","year":"2019","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/S0921-5093(01)01254-0","article-title":"Correlation of the M23C6 Precipitation Morphology with Grain Boundary Characteristics in Austenitic Stainless Steel","volume":"318","author":"Hong","year":"2001","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Alsmadi, Z.Y., Abouelella, H., Alomari, A.S., and Murty, K.L. (2022). Stress-Controlled Creep\u2013Fatigue of an Advanced Austenitic Stainless Steel at Elevated Temperatures. Materials, 15.","DOI":"10.3390\/ma15113984"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"139944","DOI":"10.1016\/j.msea.2020.139944","article-title":"Evolution of the microstructure and mechanical properties of HR3C austenitic stainless steel after ageing for up to 30,000 h at 650\u2013750 \u00b0C","volume":"796","author":"Sroka","year":"2020","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"607","DOI":"10.1179\/1878641315Y.0000000007","article-title":"Precipitation evolution and creep strength modeling of 25Cr20NiNbN austenitic steel","volume":"32","author":"Vujic","year":"2015","journal-title":"Mater. High Temp."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1016\/j.matchar.2007.05.017","article-title":"Investigation on the intergranular corrosion resistance of the AISI 316L(N) stainless steel after long time creep testing","volume":"59","author":"Terada","year":"2008","journal-title":"Mater. Charact."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1016\/j.scriptamat.2011.06.010","article-title":"Formation of M23C6\u2014Type precipitates and chromium\u2013depleted zone in austenite stainless steel","volume":"65","author":"Kaneko","year":"2011","journal-title":"Scr. Mater."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1016\/j.msea.2016.08.085","article-title":"Evolution of microstructure and mechanical properties of a 25Cr-20Ni heat resistant alloy after long-term","volume":"675","author":"Yan","year":"2016","journal-title":"Mater. Sci. Eng. 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