Hegde Sahib
i)What is the significance of stabilizing treatment at 950-980C with soaking for 2 hrs and cool in air even after solution annealing at 1050C followed by water quenching? Why Stabilizing treatment is necessary for H grade Ss and not in L grade SS ?
The ASM Handbook states that 'the stabilising anneal.. consists of holding at 845-900°C for up to 5h, depending on section thickness', but does not give methods of cooling or cooling rates. The Metals Handbook suggests a stabilising treatment of 2-4h at 870-900°C followed by rapid cooling to precipitate all possible carbon as Ti or Nb carbides and subsequently prevent Cr carbide precipitation. This is especially needed for H grades of stainless steels.
ii) Is there any affect on properties if we do not go for Stabilizing treatment
Yes, in effect with no stabilised treatment, you would expect that Cr carbides are formed (rather than Ti or Nb carbides) thereby reducing the corrosion resistance (primarily).
iii)What will be the microstructure of Stabilized 321H steel as against only Solution annealed
See above, you will have Cr carbides in the grain boundaries, leading to depletion of Cr in a narrow band around grain boundaries. Hence the requirement for IGC practice E.Rgds
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of PB HEGDE
Sent: 03 August 2010 05:07
To: materials-welding@googlegroups.com
Subject: RE: [MW:6271] Satbalising (Treatment of SA321H
Dear Friends
My query was particularly for H grade 321 i.e. 321 H
i)What is the significance of stabilizing treatment at 950-980C with soaking for 2 hrs and cool in air even after solution annealing at 1050C followed by water quenching? Why Stabilizing treatment is necessary for H grade Ss and not in L grade SS ?
ii) Is there any affect on properties if we do not go for Stabilizing treatment
iii)What will be the microstructure of Stabilized 321H steel as against only Solution annealed
Regards
Hegde p.B.
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Shashank Vagal
Sent: Monday, August 02, 2010 11:46 PM
To: materials-welding@googlegroups.com
Subject: Re: [MW:6262] Satbalising (Treatment of SA321H
| I am confused-
Sir
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