Comparing stainless steel surfaces: which is the right one?

[@rkhh01]

Thank you for a very interesting video. When discussing pickled tube you say that it is suitable for many, but not all, pharmaceutical applications. Can you please comment on the applications that this surface is less suitable for - and why?

[@theomicottis3388]

Thank you for sharing this information. Is the pickling following by passivation?

[@DockweilerAG]

Thank you for your question! The pickled material will be rinsed afterwards to clean it from remains of hydrofluric acid and loose residuals inside. Afterwards it’s soaked in diluted nitric acid to passivate. The final cleaning step is purging with DI water and drying with pure nitrogen. If there are any questions left, please let us know!

[@theomicottis3388]

@@DockweilerAG Many thanks for your reply. What kind of test do you use in order to verify that pickling was properly done? Cooper sulfate?

[@DockweilerAG]

@@theomicottis3388 We apply first of all a careful material pre-qualification. In the next steps we control the process parameters of the pickling very well (Acid concentration, Temperature, duration). Random checks are executed by ASTM G61 or we optionally make use of KorroPad Testing in order to identify defects in the passive layer.

[@ankitpadaliya2105]

what is chemical cleaning process..is it different than electropolishing..

[@DockweilerAG]

Thank you for your feedback. There are different cleaning processes. 1. Pickling: unspecific surface removal - matt surface 2. P3 cleaning: no surface removal - only degreasing 3. Electropolishing: Cleaning and smoothing of the surface For more information have a look to our video “Surfaces: Which is the right one”. Or send us an e-mail to [e-mail]