| Autor: |
Ravindran Rejeesh, Rakesh Kumar Barik, Rahul Mitra, Andrii Kostryzhev, Chitta R. Das, Shaju K. Albert, Debalay Chakrabarti |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Metals, Vol 13, Iss 6, p 1124 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2075-4701 |
| DOI: |
10.3390/met13061124 |
| Popis: |
The present study investigates the relative effect of B and N concentrations and the austenitization temperature on the microstructure and mechanical properties (tensile and Charpy impact) of modified 9Cr-1Mo (P91) steels. Initially, a B-free P91 steel (with 500 ppm N) and four different B-containing steels (25–100 ppm) with varying N concentrations (20–108 ppm) were hot-rolled, normalized from different austenitization temperatures (1000–1100 °C/1 h) and finally tempered at 760 °C for 1 h. A Charpy impact test shows that the ductile–brittle transition temperature (DBTT) of all the B-added steels decreases with an increase in the austenitization temperature, where the 100 ppm B steel offers the lowest DBTT (−85 °C). Similarly, the strength increases with the increase in the austenitization temperature (1100 °C), with a slight drop in ductility. The influence of precipitates on the microstructure and mechanical properties is explained considering the B enrichment at the precipitates and the thermodynamic stability of the precipitates. The 100 ppm B steel (containing the maximum B and minimum N), normalized from 1100 °C austenitization, shows the best combination of tensile and Charpy impact properties, owing to the effective dissolution of coarse M23C6 and MX precipitates during the normalization treatment and the formation of fine B-rich (Fe,Cr)23(B,C)6 precipitates during the subsequent tempering. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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