Microstructural evolution during quenching and partitioning of 0.2C-1.5Mn-1.3Si steels with Cr or Ni additions
| Autor: | D.T. Pierce, A. Hood, E. De Moor, Amy J. Clarke, D. L. Williamson, Jonathan D. Poplawsky, D.R. Coughlin, Kester D. Clarke, John G. Speer, B. Mazumder |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Polymers and Plastics Alloy Analytical chemistry chemistry.chemical_element 02 engineering and technology Atom probe engineering.material 01 natural sciences Carbide law.invention law 0103 physical sciences Mössbauer spectroscopy 010302 applied physics Quenching Austenite Metals and Alloys 021001 nanoscience & nanotechnology Decomposition Electronic Optical and Magnetic Materials chemistry Ceramics and Composites engineering 0210 nano-technology Carbon |
| Zdroj: | Acta Materialia. 151:454-469 |
| ISSN: | 1359-6454 |
| DOI: | 10.1016/j.actamat.2018.03.007 |
| Popis: | The influence of Cr and Ni additions and quench and partition (Q&P) processing parameters on the microstructural development, including carbide formation and austenite retention during Q&P, was studied in two steels with a base composition of 0.2C-1.5Mn-1.3Si wt.% and additions of 1.5 wt.% Cr (1.5Cr) or Ni (1.5Ni). Additions of 1.5 wt.% Cr significantly slowed the kinetics of austenite decomposition relative to the 1.5Ni alloy at all partitioning temperatures, promoting greater austenite retention, lower retained austenite carbon (C) contents, and reduced sensitivity of the retained austenite amounts to processing variables. In the 1.5Cr alloy after partitioning at 400 °C for 300 s, η-carbides were identified by transmission electron microscopy (TEM) and atom probe tomography (APT) revealed no significant enrichment of substitutional elements in the carbides. In the 1.5Ni alloy after partitioning at 450 °C for 300 s, both plate-like and globular carbides were observed by TEM. APT analysis of the globular carbides clearly revealed significant Si rejection and Mn enrichment. Mossbauer effect spectroscopy was used to quantify the amount of carbides after Q&P. In general, carbide amounts below ∼0.3% of Fe were measured in both alloys after partitioning for short times (10 s), irrespective of quench or partitioning temperature, which corresponds to a relatively small portion of the bulk C. With increasing partitioning time, carbide amounts remained approximately constant or increased, depending on the alloy, quench temperature, and/or partitioning temperature. |
| Databáze: | OpenAIRE |
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