Summary for stainless steel polishing problems Discussion
Stainless steel polishing problems are discussed around Paul Clancy’s report of hydrogen bubbles appearing on the surface during polishing. He suspected heat from the polishing process, but Martin Trigg-Hogarth, a ferrous metallurgist, challenged that explanation and said heat of grinding would not normally create bubbles from within the metal. Instead, he asked for more detail before diagnosing the issue: the stainless grade, whether the material is sheet, plate, or casting, the size of the bubbles, and whether the process is mechanical polishing or electropolishing. The thread does not reach a final fix, but it makes clear that the cause cannot be assumed from heat alone and that the polishing method and base material details are essential to identifying the real source of the defect.
I am polishing stainless steel and I have a problem with hydrogen bubbles appearing in the surface. I believe this is caused from heat in the polishing process. How can I prevent this? Your comments would be appreciated.
Regards,
Paul Clancy
Austal Ships – Henderson, Western Australia, Australia
2001
 | A. I thought that most electro-polishing was done with the work anodic. Thus you get oxygen produced. Also I thought this was normal. I find the best thing to do with electro-polishing is steer well clear of it! If you wish to do electro-polishing may I suggest your next question is – where can I find out about electro-polishing? One thing to do about the bubbles may be to agitate the work manually.
A. As a ferrous metallurgist, I can’t accept an explanation of “heat of grinding” producing such bubbles from within the metal. What grade of stainless? What form (eg, sheet, plate, casting)? What size “bubbles”? Are we talking mechanical polishing here, or electropolishing?
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