From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable Phase
Austenitic stainless steels are employed in many industrial fields, due to their excellent corrosion resistance, easy formability and weldability. However, their low hardness, poor tribological properties and the possibility of localized corrosion in specific environments may limit their use. Conven...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-01-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/10/2/187 |
| _version_ | 1818177792797310976 |
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| author | Francesca Borgioli |
| author_facet | Francesca Borgioli |
| author_sort | Francesca Borgioli |
| collection | DOAJ |
| description | Austenitic stainless steels are employed in many industrial fields, due to their excellent corrosion resistance, easy formability and weldability. However, their low hardness, poor tribological properties and the possibility of localized corrosion in specific environments may limit their use. Conventional thermochemical surface treatments, such as nitriding or carburizing, are able to enhance surface hardness, but at the expense of corrosion resistance, owing to the formation of chromium-containing precipitates. An effective alternative is the so called low temperature treatments, which are performed with nitrogen- and/or carbon-containing media at temperatures, at which chromium mobility is low and the formation of precipitates is hindered. As a consequence, interstitial atoms are retained in solid solution in austenite, and a metastable supersaturated phase forms, named expanded austenite or S phase. Since the first studies, dating 1980s, the S phase has demonstrated to have high hardness and good corrosion resistance, but also other interesting properties and an elusive structure. In this review the main studies on the formation and characteristics of S phase are summarized and the results of the more recent research are also discussed. Together with mechanical, fatigue, tribological and corrosion resistance properties of this phase, electric and magnetic properties, wettability and biocompatibility are overviewed. |
| first_indexed | 2024-12-11T20:37:43Z |
| format | Article |
| id | doaj.art-610535ea2b3141df915582a1cfc0da78 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-11T20:37:43Z |
| publishDate | 2020-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-610535ea2b3141df915582a1cfc0da782022-12-22T00:51:37ZengMDPI AGMetals2075-47012020-01-0110218710.3390/met10020187met10020187From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable PhaseFrancesca Borgioli0Department of Industrial Engineering, University of Florence, via S. Marta 3, 50139 Florence, ItalyAustenitic stainless steels are employed in many industrial fields, due to their excellent corrosion resistance, easy formability and weldability. However, their low hardness, poor tribological properties and the possibility of localized corrosion in specific environments may limit their use. Conventional thermochemical surface treatments, such as nitriding or carburizing, are able to enhance surface hardness, but at the expense of corrosion resistance, owing to the formation of chromium-containing precipitates. An effective alternative is the so called low temperature treatments, which are performed with nitrogen- and/or carbon-containing media at temperatures, at which chromium mobility is low and the formation of precipitates is hindered. As a consequence, interstitial atoms are retained in solid solution in austenite, and a metastable supersaturated phase forms, named expanded austenite or S phase. Since the first studies, dating 1980s, the S phase has demonstrated to have high hardness and good corrosion resistance, but also other interesting properties and an elusive structure. In this review the main studies on the formation and characteristics of S phase are summarized and the results of the more recent research are also discussed. Together with mechanical, fatigue, tribological and corrosion resistance properties of this phase, electric and magnetic properties, wettability and biocompatibility are overviewed.https://www.mdpi.com/2075-4701/10/2/187austenitic stainless steelsexpanded austenites phaselow temperature treatmentslow temperature nitridinglow temperature carburizingsurface engineering |
| spellingShingle | Francesca Borgioli From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable Phase Metals austenitic stainless steels expanded austenite s phase low temperature treatments low temperature nitriding low temperature carburizing surface engineering |
| title | From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable Phase |
| title_full | From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable Phase |
| title_fullStr | From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable Phase |
| title_full_unstemmed | From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable Phase |
| title_short | From Austenitic Stainless Steel to Expanded Austenite-S Phase: Formation, Characteristics and Properties of an Elusive Metastable Phase |
| title_sort | from austenitic stainless steel to expanded austenite s phase formation characteristics and properties of an elusive metastable phase |
| topic | austenitic stainless steels expanded austenite s phase low temperature treatments low temperature nitriding low temperature carburizing surface engineering |
| url | https://www.mdpi.com/2075-4701/10/2/187 |
| work_keys_str_mv | AT francescaborgioli fromausteniticstainlesssteeltoexpandedaustenitesphaseformationcharacteristicsandpropertiesofanelusivemetastablephase |