Ha, Vu The Jung, Woo Sang Suh, Jin Yoo 2024-01-20T16:02:48Z 2024-01-20T16:02:48Z 2021-09-04 2011-11 1073-5623 https://pubs.kist.re.kr/handle/201004/129856 Austenitic stainless steels are expected to be a major material for boiler tubes and steam turbines in future ultra-supercritical (USC) fossil power plants. It is of great interest to maximize the creep strength of the materials without increasing the cost. Precipitation strengthening was found to be the best and cheapest way for increasing the creep strength of such steels. This study is concerned with improving creep properties of a high nitrogen Nb-stabilized 15Cr-15Ni austenitic alloy through introducing a high number of nanosized particles into the austenitic matrix. The addition of around 4 wt pct Mn and 0.236 wt pct N into the 15Cr-15Ni-0.46Si-0.7Nb-1.25Mo-3Cu-Al-B-C matrix in combination with a special multicycled aging-quenching heat treatment resulted in the fine dispersion of abundant quantities of thermally stable (Nb,Cr,Fe)(C,N) precipitates with sizes of 10 to 20 nm. Apart from the carbonitrides, it was found that a high number of coherent copper precipitates with size 40 to 60 nm exist in the microstructure. Results of creep tests at 973 K and 1023 K (700 A degrees C and 750 A degrees C) showed that the creep properties of the investigated steel are superior compared to that of the commercial NF709 alloy. The improved creep properties are attributed to the improved morphology and thermal stability of the carbonitrides as well as to the presence of the coherent copper precipitates inside the austenitic matrix. English SPRINGER HIGH-TEMPERATURE CREEP PRECIPITATION Improved Creep Behavior of a High Nitrogen Nb-Stabilized 15Cr-15Ni Austenitic Stainless Steel Strengthened by Multiple Nanoprecipitates Article 10.1007/s11661-011-0752-6 1 METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, v.42A, no.11, pp.3378 - 3385 METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE 42A 11 3378 3385 scie scopus 000295038900019 2-s2.0-80053567779 Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Materials Science Metallurgy & Metallurgical Engineering Article HIGH-TEMPERATURE CREEP PRECIPITATION Austenitic stainless steel Creep behavior (Nb,Cr,Fe)(C,N) precipitates