Dear Dr. Jastej Singh,

for the chemical etching, you can try the following solutions:

1) a glycerol solution of HNO3, HCl and HF;

2) a solution with 12 ml HCl + 2 ml HNO3 + 2 ml ethanol using stirring-immersion from 15 to 30 sec.. Pay attention, you should have about 1-3 minutes before it reacts.

Best regards, Pierluigi Traverso

Thank you for the contribution sir Pierluigi Traverso . Sir, Can you please give an idea about proportions of HNO3, HCl and HF . Also, what is your opinion about

CuCl2 + HCl + Ethanol as an etchant for same purpose as I have read this etchant in few papers.

Hi, you may have a closer look at Struers Application Note for Metallographic Preparation of Stainless Steels @ https://www.struers.com/-/media/Struers-media-library/Materials/Application-reports/AN-6-Stainless-Steel_2016_ENG.pdf

We mainly use Beraha II for SEM preparation of DSS.

Best regards,

Andreas

Thank you sir Andreas Heyn .

Sir, the use of Beraha II (as it contains K2S2O5 reagent), gave false Sulfur signal during EDS measurements in my experience, although it reveals the phases satisfactorily.

Please have a look for this report. it might be useful for you...

All the best

Dear Dr. Jastej Singh,

the etching solution containing the three acids and glycerol is of quite recent and "unconventional" (as from paper: "Effect of Etching Methods in Metallographic Studies of Duplex Stainless Steel 2205" , Metal Science and Heat Treatment 58 (11) March 2017 - Authors : Alptekin Kısasöz, Ahmet Karaaslan Y. Bayrak). The authors did not indicate the exact proportions; if I had to do the chemical attack, I would try 10 ml HNO3, 10 ml HF, 30 ml HCl and 50 ml Glycerol; with an immersion time from seconds to minutes. The solution you propose, I think 2g CuCl2, 40 ml HCl and 40-80 ml of Ethanol or Methanol (95%), could be fine (ASTM E 407-99 regulation); in general, it attacks ferrite more readily than austenite.

Best regards, Pierluigi Traverso.