Bright chrome is often used as a decorative feature on consumer products such as cars.

Chrome plating is a finishing treatment utilizing the electrolytic deposition of chromium. The most common form of chrome plating is the thin, decorative bright chrome, which is typically a 10 µm layer over an underlying nickel plate. It imparts a mirror-like finish to items such as metal furniture frames and automotive trim. Thicker deposits, up to 1000 µm, are called hard chrome and are used in industrial equipment to reduce friction and wear and to restore the dimensions of equipment that has experienced wear. Black chrome is a variant in which process conditions are altered to give the plating a dark color. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Electroplating is the process of using electrical current to coat an electrically conductive object with a relatively thin layer of metal. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... This article or section is in need of attention from an expert on the subject. ... A micrometre (American spelling: micrometer, symbol µm) is an SI unit of length equal to one millionth of a metre, or about a tenth of the size of a droplet of mist or fog. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Atomic mass 58. ... A mirror, reflecting a vase. ... Friction is the force that opposes the relative motion or tendency toward such motion of two surfaces in contact. ...

Chromium plating solutions

There are two types of chromium plating: industrial and decorative. Industrial chromium plating is also referred to as Hard Chrome or Engineered Chrome. There are two types of Industrial chromium plating solutions:

1. Hexavalent chromium baths whose main ingredient is chromic anhydride.
2. Trivalent chromium baths whose main ingredient is chromium sulfate or chromium chloride. Trivalent chromium baths are not yet common, due to restrictions concerning color, brittleness, and plating thickness.

Chromium hexavalent Cr(VI) compounds, often called hexavalent chromium, exist in several forms. ...

Typical bath composition and operation of the hexavalent bath

• Chromic acid (CrO₃): 250–300 g/l.
• Sulfuric acid: 2.5–3.0 g/l.
• Operating temperature: 45 to 60 °C.
• Plating current: 1.55–3.10 kiloamperes per square meter DC.
• Maximum superimposed AC ripple allowed is 18%, preferred ripple is 5% to 10%.
• Anodes: lead with up to 7% tin or antimony.
• Chromium may be stripped anodically in an aqueous solution of sodium hydroxide.

In chemistry, chromic acid is a chromium (Cr) compound, yet to be isolated, with the formula H2CrO4. ... Sulfuric acid, H2SO4, is a strong mineral acid. ... Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... City lights viewed in a motion blurred exposure. ... For Pb as an abbreviation, see Pb. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Standard atomic weight 118. ... General Name, Symbol, Number antimony, Sb, 51 Chemical series metalloids Group, Period, Block 15, 5, p Appearance silvery lustrous grey Atomic mass 121. ... Sodium hydroxide (NaOH), also known as lye or caustic soda, is a caustic metallic base. ...

Quality requirements

Hard chromium layers (over 10 micrometres) can be used in various applications and consequently subject to different types of quality requirements. Hard chromium layers on piston rods of hydraulic cylinders are tested on corrosion resistance in salt spray cabinets. Because these are destructive tests, only representative sample material can be tested. The salt spray solutions and the conditions in the cabinet are normed as well as the evaluation of the result after the test. The duration of the test is depending the agressivity of the test and the standard the industry has developed for this type of materials. In general there is a requirement that the deposit be uniform in thickness on all surfaces, and should be smooth, homogeneous and free from frosty areas, pin holes, pits, nodules, and other defects.

See also

• Stainless steel

Chromium plating specifications, including quality requirements, can be found in the following documents: AMS 2406K, Plating, Chromium Hard Cock Deposit AMS-QQ-C-320, Chromium Plating (Electrodeposited). The 630 foot high, stainless-clad (type 304) Gateway Arch defines St. ...