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[MW:2926] Re: SS 410

By Materials & Welding
Dear Amarjit,

Its not advisable to carry out pickling and passivation on 410 / 405 grade of SS as the same is not fully austenitic SS and hence are not good corrosion resistant as the Cr % are not equal to or more than 12% which is the basic requirement to have the resistance to corrosion.

Discolourisation / blackish / redish surface observed after Stress relieving.

The best way to clean the surface is using glass grit blasting whihc gives shiny surface of SS and easy to clean.

To verify that there is no iron contamination or embaded CS particle, CUSO4 test can be carried out and another visual check shall be made after 8 hrs to verify that there is no contamination exist.

Regards
 
C. K. Purohit
Eng-Tech Weld1
Sr Welding Inspector


8/11 Amarjit Singh <amritas2001@gmail.com>

Hi,

Can anybody guide for the following
1) In case of SS 410 Cald vessels, pickling & passivation is required
to be done after fabrication. But as the components are stress
relieved after clad restoration the surface of 410 weld are & clad
also does not get cleaned properly after pickling.
2) The pickling is generally carried out as per ASTM A380
3) Is there any better pickling agent which can give better surface
after pickling ? What is the ratio if it is a mixture? What is the
time & temperature of application.

regards,
Amarjit singh
0091-9867506448


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