Effect of Cr Content on the Microstructure and Mechanical Properties of 0.03C-XCr-14Ni-2.3Mo-0.35Nb-Fe Austenitic Stainless Steel
Based on the standard composition of 316 L alloy， a type of Cr， Ni， and Nb strengthened austenitic stainless steel （denoted as 0.03C-XCr-14Ni-2.3Mo-0.35Nb-Fe steel） was designed. Analytical techniques such as optical microscopy （OM）， scanning electron microscopy （SEM）， transmission electron microsco...
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| Format: | Article |
| Language: | zho |
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Editorial Office of Special Steel
2025-08-01
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| Series: | Teshugang |
| Subjects: | |
| Online Access: | https://www.specialsteeljournal.com/fileup/1003-8620/PDF/2025-00044.pdf |
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| Summary: | Based on the standard composition of 316 L alloy， a type of Cr， Ni， and Nb strengthened austenitic stainless steel （denoted as 0.03C-XCr-14Ni-2.3Mo-0.35Nb-Fe steel） was designed. Analytical techniques such as optical microscopy （OM）， scanning electron microscopy （SEM）， transmission electron microscopy （TEM）， tensile testing， and impact testing were employed to investigate the microstructures and mechanical properties of hot-rolled plates with three Cr contents （16%， 18%， and 21%） in both solution-treated and aged states （aged at 400 ℃for 1 000 hours）. The results indicate that the main precipitated phases in the alloy are NbC and delta-ferrite. With increasing Cr content， the volume fraction of delta-ferrite significantly increases， while the quantity of NbC remains nearly unchanged. After thermal aging for 1 000 hours， the delta-ferrite phase remains stable， and no new phases are observed， with minor fluctuations in mechanical properties. As Cr content increases， the room-temperature and 350 ℃tensile yield strength and ultimate tensile strength of both solution-treated and aged alloys show slight upward trends. However， the elongation and impact energy exhibit minor variations from 16Cr to 18Cr but sharply decrease in the 21Cr alloy. The higher Cr content promotes the precipitation of delta-ferrite， leading to the formation of localized cleavage regions during fracture. This alters the fracture mode from ductile to brittle， resulting in a rapid decline in elongation and impact energy for the 21Cr alloy. |
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| ISSN: | 1003-8620 |