Autor: |
Kamran Saeidi, Sajid Alvi, Frantisek Lofaj, Valeri Ivanov Petkov, Farid Akhtar |
Jazyk: |
angličtina |
Rok vydání: |
2019 |
Předmět: |
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Zdroj: |
Metals, Vol 9, Iss 2, p 199 (2019) |
Druh dokumentu: |
article |
ISSN: |
2075-4701 |
DOI: |
10.3390/met9020199 |
Popis: |
Duplex stainless steel, 71 wt.% austenite, 13 wt.% ferrite and 16 wt.% sigma, was made upon heat treating of fully ferritic as-built selective laser melted (SLM) 2507 stainless steel at 1200 °C. Formation of sigma phase in the heat treated SLM 2507 was investigated using optical microscopy and scanning electron microscopy (SEM). The heat treated SLM 2507 demonstrated a yield strength of 686 MPa, ultimate tensile strength of 920 MPa and an elongation of 1.8% at room temperature with a brittle fracture morphology. Precipitation of sigma phase during heat treatment and slow cooling improved the mechanical and wear properties at high temperatures (1200 °C and 800 °C, respectively). The tensile strength and elongation of the heat treated SLM 2507 was measured 400 MPa and 20% as compared to casted duplex steel with 19 MPa and 30% elongation at 1200 °C. The 20 times higher mechanical strength as compared to casted duplex steel was attributed to sigma precipitates. Tribological behaviour of heat treated duplex SLM 2507 containing sigma at 800 °C showed very low wear rate of 4.5 × 10−5 mm3/mN compared to casted duplex steel with 1.6 × 10−4 mm3/mN. |
Databáze: |
Directory of Open Access Journals |
Externí odkaz: |
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