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Study on Properties of Hyper-duplex Stainless Steel 7A of ASTM A-890 (CD3MWN)

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Abstract

Hyper-duplex stainless steel castings of grade 7A of ASTM A-890 are comparatively new in duplex series, and their regular production has not yet been started like other super-duplex grades 5A and 6A. In view of this, a study has been undertaken to find out the properties of this grade under different experimental conditions. Tensile properties and hardness are found to be higher than other super-duplex grades; however, impact values at − 50 °C are lower than grade 6A. Pitting corrosion, critical pitting temperature and intergranular corrosion tests were carried out as per ASTM standard. Potentiodynamic polarization scan was carried out and compared with 6A. Deleterious phases were formed by holding samples for a shorter time at 1000 °C with a corresponding increase in hardness and drop in ferrite content. 475 °C embrittlement effect was studied and compared with other duplex grades. Re-dissolution of harmful precipitates was carried out at 550 °C by varying time to study any change in properties. Some of the properties of grade 7A were compared with wrought product of hyper-duplex grade, UNS S32707. Low-temperature impact values of hot-worked cast 7A test block were improved considerably in both longitudinal and transverse direction. Dry sliding wear resistance test was carried out as per ASTM standard, and values were found to be better than grade 6A.

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References

  1. International Molybdenum Association (IMOA), Practical Guidelines for the Fabrication of Duplex Stainless Steels, IMOA, London, UK (2009), p. 10.

  2. Paulraj P, and Garg R, Adv Sci Technol Res J9 (2015) 87. https://doi.org/10.12913/22998624/59090.

    Article  Google Scholar 

  3. ASTM A890/A890M-13 Standard Specification for Castings, Iron–Chromium–Nickle–Molybdenum Corrosion Resistant, Duplex (Austenitic/Ferritic) for General Application.

  4. Charles J, Chemelle P, Past, present and future of the duplex stainless steels, 8th Duplex Stainless Steels conference, 13–15 Oct 2010, Beaune, France. http://www.stainless-steel-world.net/pdf/Duplex_families_and_applications_A_review_Part_1.pdf.

  5. Ogawa K, and Osuki T, ISIJ Int59 (2019) 122. https://doi.org/10.2355/isijinternational.ISIJINT-2018-477.

    Article  CAS  Google Scholar 

  6. Chen T H, and Yang J R, Mater Sci Eng A311 (2001) 28. https://doi.org/10.1016/S0921-5093(01)00911-X.

    Article  Google Scholar 

  7. Escriba D M, Materna-Morris E, Plaut R L, and Padilha A F, Mater Charact60 (2009),1214. https://doi.org/10.1016/j.matchar.2009.04.013.

    Article  CAS  Google Scholar 

  8. Charles J, Duplex families and applications: a review Part 1: From Duplex Pioneers up to 1991, Proceedings of the Conference Duplex Stainless Steels ‘91, Beaune, France (1991), vol. 1, p. 3.

  9. Solomon H D, and Levinson L M, Acta Metallurgica26 (1978) 429. https://doi.org/10.1016/0001-6160(78)90169-4.

    Article  CAS  Google Scholar 

  10. Sahu J K, Krupp U, Ghosh R N, and Christ H J, Mater Sci Eng A508 (2009) 1. https://doi.org/10.1016/j.msea.2009.01.039.

    Article  CAS  Google Scholar 

  11. ASTM E 562 Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count.

  12. ASTM G 48 Standard Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride Solution.

  13. ASTM A262-15 Standard Practices for Detecting Susceptability to Intergranular Attack in Austenitic Stainless Steels.

  14. ASTM G99-17 Standard Test Method for Wear Testing with a Pin-on-Disk Apparatus.

  15. Sandvik SAF 2707 HD–Sandvik Materials Technology.

  16. Raha B, Mater Today Proc5 (2018) 7836. https://doi.org/10.1016/j.matpr.2017.11.464.

    Article  CAS  Google Scholar 

  17. Martins M, Caseletti L C, Mater. Charact., 55 (2005), 225. https://doi.org/10.1016/j.matchar.2005.05.008.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We express sincere gratitude to the management of Peekay Steel and staff members of Mechanical Engineering Department of NIT Calicut for their contribution towards the completion of the work. The authors particularly acknowledge Mr. A.K. Rastogi, Chief Technology Officer, and Mr. K.E. Shanavaz, Joint Managing Director, of Peekay Steel Castings for their keen interest in this work and constant encouragement during the project.

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  1. Peekay Steel Castings (P) Ltd., Calicut, Kerala, 673027, India

    Barundeb Raha

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Raha, B. Study on Properties of Hyper-duplex Stainless Steel 7A of ASTM A-890 (CD3MWN). Trans Indian Inst Met 73, 127–134 (2020). https://doi.org/10.1007/s12666-019-01811-z

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