METAL FINISHING

Metal Finishing Services

Metal Finishing Services Include:

Passivation
Oil and grease removal
Rust removal
Tumble deburring
Vibratory deburring

What is Passivation?

Passivation removes “free iron” contamination that is left on the surface of stainless steel after the machining and fabricating process. By nature, stainless steel is self-passivating. The chromium in the alloy reacts to the oxygen in the air, creating a thin oxide film around it. This film is chemically inert and self-repairing when scratched. “Free iron” contaminants that aren’t removed from the part can hinder the formation of an oxide layer, creating a potential corrosion site. If the “free iron” sites were uncommon on the surface, then the chance of corrosion would be small. However, the machining and fabricating process can’t prevent these “free iron” sites from covering the surface of your part, allowing it to corrode prematurely. Mechanical removal of the “free iron” isn’t practical due to part deformation and the complex nature of some parts. The non-mechanical passivation process is the perfect final step in creating stainless steel parts that are free from “free iron” corrosion sites. The passivation process Rite-Way Black & Deburr uses conforms to the most commonly referenced industry specification, Fed. Specs AMS 2700 and ASTM A967.

Our passivation specs include but are not limited to:
  • QQ-P-35
  • ASTM-A967
  • MIL-STD-171-5.4.1
  • AMS-2700

Our Passivation Process

The first step in our passivation process is to determine if different alloys are present within your part. This is an important step because the type of stainless steel being processed determines the passivation method. Parts of the same alloy are then immersed in a Metkleen 2150 heated cleaner bath for 10 to 20 minutes to remove oil, polishing compounds, or any other foreign material on the surface. Parts are then immersed in a descaler to remove heat treat scale and discoloration. 

The next step, and the most critical, is selecting the time the parts will be in the chemical bath, determining the necessary temperature, and calculating the right concentration of nitric acid in the bath. An incorrect calculation for any of these variables produces unwanted results. After the part is immersed in the proper bath for the right amount of time, the final step, rinsing and drying the part, is completed. The success of this process is determined by how well the part was machined and/or heat treated. Poor machining introduces contaminants into the alloy, which effects the bath variable calculations and produces poor results. Poor heat treating can lead to discoloration of the part, which cannot be removed by passivation.
Same-Day Turnaround
Available. Please Call for Details.
Call 937-224-7762 or stop by 1138 E. Second St., Dayton, OH 45403 to set up your metal finishing service.
Share by: