Q. We are doing 120 microns on steel rings in conventional baths.After plating 120 microns we found that roughness on the job. How to avoid the roughness. In the same bath, same job when we do 30 microns are not getting roughness.
A. Chromium will mirror what's underneath..(base metal) Reverse etch (if you are using reverse etch) can exacerbate the problem and make a poor finish even worse.
Recommend access the base metal. Know your material content and heat treatment (tensile strength of the metal) Prepare the base metal with the utmost care, Good micro-finish going in, good micro-finish coming out.
Observe reverse etch times, and make sure your anodes are in good shape, properly spaced from the plating surface, large enough and sized correctly to do the job.
If your pre-chrome finish is smooth, your post-chrome finish should be smooth.
Best of luck.