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Surface Cleaning and Finishing for type 410 AISI Stainless Steel

I use type 410 AISI, Stainless Steel for the production of our Surgical and Dental Instruments, such as Forceps, Tweezers, Scissors, etc, etc,. As I am facing problem of rusting at the boxlock or where the milling work is perfomed. I had used several methods for the passivation. Can any one help me out in getting the precise passivation formulation and other methods for the pickling and cleaning of Instruments, both acidic or alkali methods for the AISI 410 type Stainless Steel.

Farooq Mirza
- Pakistan
1998

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1998

In a vibratory finishing process, I have used a two step process to clean rust from hinge areas of forceps, recessed areas (such as ID stamps) and knurled handles of dental instruments. This is used on several Stainless Steel alloys of which AISI 410 is certainly one.

Step 1: Inhibited Hydrochloric Acid (HCl) 10% by volume for 10-15 minutes. Inhibition of the HCl is important to avoid loss of any metal surface aesthetics

Step 2: Rinse/neutralized with mild alkaline burnishing compound 1-2% by volume (pH 8.5-9.5) 20-30 minutes.

I suggest you contact REM Chemicals, Inc. in Southington, CT USA. They have extensive experience with acid/alkaline surface treatment processes for surgical instruments.

I hope this is of some help.

Bill

Bill Boatright

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1998

If your product is suitable for electropolishing, you may find the corrosion resistance can be vastly improved over the standard processes recommended for passivation. Electropolishing has the capability to remove iron from the metal surface, leaving a film which consists essentially of the oxides of chromium.

Electropolishing will require a good quality steel, more equipment, and more attention to detail, but the results may be worth the extra trouble. An outline of the process can be found on our web site.

Ed Bayha
Metal Coating Process Corporation - Charlotte, North Carolina