Conference Papers

Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506

Browse

Subject: search.filters.subject.Aging

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Effect of reversion heat treatment on the mechanical properties of thermally embrittled UNS S32760 duplex stainless steel
    (Trans Tech Publications Ltd ttp@transtec.ch, 2015) Natesh, M.; Shamanth, V.; Ravishankar, K.S.
    Duplex Stainless Steels contain very high chromium contents (19-30% by weight) and exhibit excellent corrosion resistance and extremely good mechanical properties. Embrittlement of duplex stainless steels due to precipitation of αʹ upon prolonged exposure in the temperature range of 280°C to 500°C has been a serious limiting factor for its long term usage in the nuclear industry, where the operating temperatures of cooling pipes is around 300°C. In this investigation, the effect of reversion heat treatment on the mechanical properties of a thermally embrittled duplex stainless steel has been studied. The specimens were solutionized, aged and then reversion treated for varying periods. The aged specimens showed significant increase in tensile strength and decrease in ductility in comparison to the ones in solutionized condition. The specimens which were reversion treated showed marginal decrease in tensile strength and significant increase in ductility after 5 minutes of holding time. As the holding time increased, the tensile strength rapidly decreased and ductility increased initially up to 30 minutes of reversion, after which there was no significant change in strength and ductility. © (2015) Trans Tech Publications, Switzerland.
  • No Thumbnail Available
    Item
    Impact On Leaching Behaviour Of Toxic Metals In Ferrochrome Ash With Varying Ph Levels
    (American Institute of Physics Inc., 2022) Krishnamurthy, M.P.; Devatha, C.P.
    In the current investigation, leaching behaviour of cobalt (Co), copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), nickel (Ni), lead (Pb) and selenium (Se) from fresh and aged Ferrochrome Ash (FCA) samples were studied under various pH conditions (3-11). Results reveal that most of the elements follow oxyanionic leaching pattern where increase in pH increases the effluent concentration of elements. Leached As, Pb, Hg, Ni and Fe reached peak concentration at alkaline phases. Cd, Cr and Zn followed cationic leaching pattern where increase in pH decreases the concentration. Any specified pattern of leaching is not followed by Ca, Se, Co and Cu. Results of leaching test reveal that the high concentration of chromium leaching was found to be 156.18 and 155 mg/L, concentration of arsenic 13.46 and 12.89 mg/L, concentration of mercury 10.23 and 10.4 mg/L and lead concentration of 6.58 and 6.72 mg/L for fresh and aged FCA ashes respectively. Hence Cr, As, Hg and Pb are identified as significant hazardous pollutants and must not be discharged without being solidified/stabilized. Leached element concentration was not affected significantly by aging of the FCA. © 2022 American Institute of Physics Inc.. All rights reserved.