Black Oxide Coating Steel

It is a deposited copper selenium compound.

Black oxide coating steel.

To achieve maximal corrosion resistance the black oxide must be impregnated with oil or wax. Blackening or adding a black oxide finish to the steel helps prevent steel from rusting by creating a chemical reaction on the metal surface. It is used to add mild corrosion resistance for appearance and to minimize light reflection. Black oxide or blackening is a conversion coating for ferrous materials stainless steel copper and copper based alloys zinc powdered metals and silver solder.

Black oxide like other coatings is used to provide protection to the part achieve a required appearance or achieve other desired properties. Epi s mid temperature black oxide process kool blak 225 blackens steel in 30 45 minutes and converts it to black iron oxide magnetite which provides a glossy black finish as well as protection for the part. Though standard black oxide is set up for steel it can be done on other substrates including stainless steel copper and brass among others. Cold black oxide is not an oxide conversion coating.

A black oxide conversion coating is applied to ferrous alloys when oxidizing salts react with the iron to form magnetite fe 3 o 4 the black oxide of iron. Hot temperature black oxide processes produce glossy black blue coatings and true black oxide magnetite finishes in 10 20 minutes. Pro tec metal s process line of hot black oxide is used to produce a true durable black oxide conversion coating on steel stainless steel and copper alloys. Instead the black oxide coating is produced by a chemical reaction between the iron on the surface of the ferrous metal and the oxidizing salts present in the black oxide.

This means that the black oxide is not deposited on the surface of the substrate like nickel or zinc electroplating. Black oxide is a form of coating used as a finish for ferrous metals stainless steel and copper and its alloys. Black oxides on stainless steel and or brass alloys will yield excellent corrosion protection primarily due to their inherent properties. Hot black oxide involves hot baths of sodium hydroxide the nasty stuff in drain cleaner nitrates and nitrites.

Black oxide can be finished by a cold process that can be done at room. Hot black oxide converts the surface into magnetite. Epi s line of high temperature blackeners offers impressive abrasion and corrosion resistance and several products meet military and ams specifications. From the black oxide process these essentially dimensionless coatings create very decorative highly durable black finishes that leave an absorbing oxide layer for oils and waxes that will provide for enhanced corrosion protection.

Black oxides on steel are not suitable for severe outdoor applications or corrosive environments but they can provide superior humidity cabinet results with proper supplementary coating. The cold processes produce a similar color but the coating tends to rub off more.