Abstract
The effect of vanadium addition on the creep property of niobium-containing 18Cr-9Ni austenitic heat-resistant steel was studied. After solution treatment, the MX precipitates of vanadium-free steel contained Nb only. On the contrary, high Nb and low V contents were detected from the MX precipitates in the steel with 0.3 wt% of vanadium. Vanadium-rich MX carbo-nitride was not observed in the matrix and at the grain boundaries after solution treatment. The vanadium precipitated as a form of Z-phase during early-stage creep deformation was attributed to the improvement in creep strength at 700 °C with applied stress higher than 150 MPa. And metallic Cu precipitates were confirmed in the nanometer scale using TEM and EDS technique. The Cu precipitates are believed to contribute to the strengthening of austenitic heat resistant steel independently. The precipitation behavior is discussed using transmission electron microscopy and thermo-kinetics simulation technique.
| Original language | English |
|---|---|
| Pages (from-to) | 532-538 |
| Number of pages | 7 |
| Journal | Journal of Alloys and Compounds |
| Volume | 574 |
| DOIs | |
| Publication status | Published - 2013 |
Bibliographical note
Funding Information:This work was supported by the POSCO specialty steel Co., Ltd. and Korea Institute of Science and Technology (Grant No. 2E24022 ). The authors would like to thank the financial support for POSCO specialty steel Co., Ltd. JYS thanks Dr. D. Tang of the FEI Company for providing their Tecnai Osirus system.
Keywords
- Austenitic stainless steel
- Creep strength
- Z-phase
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry