Engineering Partnerships That Outperform

Informative Articles

Physical and Chemical Properties of Chromium

Following are the physical and chemical properties of chromium.

A. Corrosion Resistance

Electroplated chromium has excellent resistance to a variety of corrosive environments. The following table will provide a broad, general guide to its compatibility with some corrosive materials. So many factors are involved in corrosion, such as the presence of suspended materials in the corrodent, the velocity of the corrodent or simply the quality of the plate that this table is a general guide only. Prudence with suggest that tests be conducted under actual service conditions prior to making design decisions. For assistance or for information on corrodents not listed, please consult the U.S Chrome Laboratory.


R – usually completely resistant

SA – some or slight attack, should be tested

NR – not recommended


Unless otherwise noted, inorganic materials were tested in 10% aqueous solutions at 25°C (77°F).

CORRODENT RESISTANCE
Acetic Acid, glacial  R
Acetic Acid, 50% Aq  R
Air, hot oxidizing  R
Air, hot reducing  R
Aluminum Chloride, 50% Aq  NR
Aluminum Sulfate (Alum) 25% Aq  SA
Ammonia, Aqua  R
Ammonium Chloride, Aq  SA
Aniline Hydrochloride  SA
Barium Chloride, Aq  R
Beer  R
Bezoic Acid  R
Biscuit & Bread Dough  R
Butyric Acid  SA
Calcium Chloride, Aq  SA
Calcium Hypochlorite, Aq  NR
Carbon Dioxide  R
Carbon Disulfide  R
Chlorine, moist gas  NR
Chromic Acid, Aq  SA
Chromic Chloride, Aq  SA
Citirc Acid, Aq  SA
Cupric Chloride, Aq  NR
Cupric Nitrate, Aq  SA
Cupric Sulfate, Aq  R
Dichloroacetic Acid  NR
Ethylene, Gaseous  R
Ferric Chloride, Aq  SA
Ferrous Sulfate, Aq  SA
Fruit Juices, acid  R
Glass, molten  R
Glue, hoof, hot  R
Hydrochloric Acid, Aq  NR
Hydrofluoric Acid, Aq  NR
Iodine, solid & vapor  NR
Ink, printing  R
Lactic Acid  SA
CORRODENT  RESISTANCE
 Milk  R
 Monochloracetic Acid  R
 Nitric Acid  R
 Oil, crude  R
 Olecic Acid  R
 Palmitic Acid  R
 Paper Pulp, sulfite  R
 Phenol  R
 Phytalic Acid  SA
 Phosphoric Acid, 85%  SA
 Picric Acid, Aq  R
 Plastics, vinyl  R
 Plastics, melamine or urea formaldehyde  R
 Plastics, polyethylene or polypropylene  R
 Plastics, acetal  SA
 Potassium Chloride, Aq  R
 Propionic Acid  SA
 Rubber, mixing or vulcanizing natural  R
 Soap  R
 Sodium Chloride, Aq  R
 Sodium Carbonate, Aq  R
 Sodium Hydroxide, Aq  R
 Sodium Hypochlorite, Aq  NR
 Steam, saturated  R
 Stearic Acid  R
 Succinic Acid  SA
 Sulfanilic Acid  SA
 Sulfur, molten  R
 Sulfer Dioxide, moist  R
 Sulfuric Acid, 96%  NR
 Tar, molten  R
 Trichloracetic Acid  NR
 Trichloroethylene  R
 Whiskey & Wine  R
 Zinc, molten  SA
 Zink Chloride, Aq  NR

B. Hardness Comparison

Indentation Hardness (Kg / mm²)

Aluminum, Type 1100 H18 70
Zinc 100
Steel, mild cold rolled 150
Brass, 70-30 hard 165
Stainless Steel, Type 304 165
Nickel, bright electroplated 300
Stainless Steel, Type 410 hardened 375
Steel, hardened tool steel 450
Chromium electroplated 1200 (Rc70)
USChrome-chromium-hardness.png

C. Coefficient of Sliding Friction

Hard Steel on Hard SteelDry 0.42
 Oiled 0.03
Chromium on Hard SteelDry 0.15
 Oiled 0.03
Mild Steel on Mild SteelDry 0.57
 Oiled 0.09
Nickel on Mild SteelDry 0.64
 Oiled 0.18
Chromium on Mild SteelDry 0.16
 Oiled 0.05
Hard Steel on BabbittDry 0.33
 Oiled 0.16
Mild Steel on Cast IronDry 0.23
 Oiled 0.13
Chromium on Cast IronDry 0.15
 Oiled 0.03
Aluminum on AluminumDry 1.4
 OiledN/A
Mild Steel on AluminumDry 0.47
 OiledN/A

D. Coefficient of Linear Expansion

8.1 X 10-6cm/cm/°C

4.5 X 10-6in/in/°F

 

COMPARISON WITH OTHER MATERIALS

Material cm/cm/°C at 20°C in/in/°F at 68°F
Aluminum (99.9+) 22.5 X 10-6 12.5 X 10-6
Brass (70Cu-30zn) 19.8 X 10-6 11 X 10-6
Cast Iron (Gray) 10.44 X 10-6 5.8 X 10-6
Chromium 8.1 X 10-6 4.5 X 10-6
Monel (70Ni-30Cu) 14.4 X 10-6 8 X 10-6
Steel (1040) 11.34 X 10-6 6.3 X 10-6
Steel (18Cr-8Ni Stainless) 9.0 X 10-6 5 X 10-6
Titanium (99.0%) 8.55 X 10-6 4.75 X 10-6

VARIATION WITH TEMPERATURE

Temperature Range, CCoefficient of Linear Expansion cm/cm/°C
20-4008.4 X 10-6
20-6009.2 X 10-6
20-8009.8 X 10-6
20-105011.0 X 10-6

We're ready to work with you.

We’re confident US Chrome will be your best option for your chrome plating applications because of our engineering approach, exceptional customer service, and regional locations. Contact us now with your questions or coating challenges.
We’ll help you find the right answer.

We serve cookies on this site to analyze traffic, remember your preferences, and optimize performance.