Yin, Feng-Shi Jung, Woo-Sang 2024-01-20T22:02:14Z 2024-01-20T22:02:14Z 2021-09-03 2009-02 1073-5623 https://pubs.kist.re.kr/handle/201004/132777 Nanosized MX precipitates in ultra-low-carbon ferritic/martensitic heat-resistant 9Cr-W-Mo-VNbTiN steels were characterized by transmission electron microscope (TEM) using carbon film replicas. The steels were prepared by vacuum induction melting followed by hot forging and rolling into plates. The plates were normalized at 1100 A degrees C for 1 hour, cooled in air, and tempered at 700 A degrees C for 1 hour. The results show that bimodal nanosized MX precipitates distribute densely and homogeneously in the matrix within martensitic lath after normalizing-and-tempering heat treatment. The larger nanosized MX precipitates with the size of 30 to 50 nm are rich in Nb, while the smaller ones with the size of about 10 nm contain less Nb but more V. Small addition of Ti causes an increase in the number of the larger nanosized MX precipitates. The total number density of the nanosized MX precipitates in the ultra-low-carbon ferritic/martensitic steels is measured to be over 300/mu m(2), much higher than that in conventional ferritic/martensitic steels. Short-term creep test results show that the ultra-low-carbon ferritic/martensitic steels with high dense nanosized MX precipitates have much higher creep rupture strength than conventional ASME-P92 steel. The strength degradation of the ultra-low-carbon ferritic/martensitic heat-resistant steels during creep is also discussed in this article. English SPRINGER Z-PHASE-FORMATION CREEP STRENGTH Nanosized MX Precipitates in Ultra-Low-Carbon Ferritic/Martensitic Heat-Resistant Steels Article 10.1007/s11661-008-9716-x 1 METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, v.40A, no.2, pp.302 - 309 METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE 40A 2 302 309 scie scopus 000262565900010 2-s2.0-59149085377 Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Materials Science Metallurgy & Metallurgical Engineering Article Z-PHASE-FORMATION CREEP STRENGTH Ferritic/martensitic steel MX precipitates Creep properties