Black Oxide rust
The finishing.com Hotline - Serious Education ... plus the most fun you can have in metal finishing
++++Q. I'm a manufacturing engineer with a plating problem. We have a long acme threaded screw which is currently finished via the zinc-iron phosphate conversion process. We are looking into the possibility of moving the manufacture of this part off-shore and are finding that zinc-iron phosphate is not a common process offshore. Black oxide is more common. How does the corrosion resistance of black oxide compare to zinc-iron phosphate. The part is used in medium voltage electrical enclosures. The part is protected from the elements, and thermostats keep the internal cubicle temperature at 4 °C above the ambient temperature to control humidity.
Bob GlowienkaManufacturer of Medium Voltage Switchgear - Wendell, North Carolina, USA ++++
A. This sounds like a benign environment where the very limited corrosion resistance of black oxide won't be a problem. But this Acme screw sounds like a moving part that requires lubricity in the finish, and I think that phosphatization offers substantially more than black oxide. I doubt that a black oxided ball screw will be a good idea. But black oxide may be what you get anyway, regardless of what you specify, if you're not there to ensure compliance.
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey++++
A. Dear Bob,
Black Oxidising on ferrous metal, also called as blackodising, is a decorative finish and has very limited corrosion resistant properties. A suitable grade of Rust Preventive oil will increase the life. If a dry film as top coat is permissible, a thin film of clear PU, epoxy or other lacquer will give far better life.
Zinc-iron, zinc-calcium, manganese-iron phosphating with suitable anti-rust oil will give longer life. Manganese phosphating produces a dark grey finish. Alternatively, zinc plating with black passivation will serve the purpose.
PRABHAKAR GUPTA- Kanpur, U.P., India(2007)
You might also like
Naturo Nitro Maximus Nitric Oxide Tablets - High Potency Nitric Oxide (No2) Booster and L-arginine Supplements - Allows You to Build Muscle Faster and Train Longer and Harder - Experience Skin Tearing Pumps That Last Hours After Training - Advanced Delivery System Fuels Your Body with 3 Different Types of Arginine Plus Citruline That Promotes Accelerated Muscle Growth and Rapid Gains - Improves Male Performance By Increasing Blood Flow to "All the Right Places" - Originally Developed for Competitive Body Builders, Cross Fitters, and Fitness Professionals - 60 Tablets Health and Beauty (Naturo Sciences)
|
(Lot of 14) 1 gram SAMPLE MATTE CP MP DIY Soap Making Pigment BLUE BLACK BROWN RED YELLOW WHITE GREEN LAVENDER VIOLET YELLOW TEAL ORANGE Titanium Dioxide Oxide Ultramarine Powder Art and Craft Supply (Powdered Up Dolly)
|
5/16" x 6" Magnetic Nut Setter - Impact Rated - Black Oxide Home Improvement (OEM Tools Direct)
|
|
Plant Guru Raw African Ivory Shea Butter for Hair and Skin, 16 oz. Beauty (Plant Guru)
|
|
TEKTON 4971 1/2-Inch Drive Impact Extension Bar Set, Cr-V, 3-Piece Home Improvement (TEKTON)
|