The Chemical Composition of Weathering Steel vs. Standard Grade 50 Steel

Chemical Composition of Weathering Steel

The Chemical Composition of Weathering Steel vs. Standard Grade 50 Steel

Steel is an alloy made up of a variety of metals — typically a combination of iron and carbon. However, other elements are added to fabricate different types of steel. From carbon steel to stainless steel, several types and categories of steel exist. The difference in each type of steel lies in its chemical composition. 

The chemical composition of standard grade 50 steel

For instance, standard grade 50 steel, also referred to as ASTM A572-50, is composed of carbon, manganese, phosphorus, sulfur and silicon. It is a high-strength, low-alloy steel with a tensile strength of 65 ksi and a tensile yield of 50 ksi. Check out the chart below for more details. 

Chemical Composition of Weathering Steel

The chemical composition of weathering steels 

Weathering steels are also high-strength, low-alloy steels with a carbon content of less than 0.2 percent, which produces adequate formability and weldability. Most weathering steels are also composed of manganese, phosphorus, sulfur, silicon, nickel, chromium, copper and vanadium. Weathering steels have a tensile strength of 70 ksi and a tensile yield of 50 ksi.

Weathering steels are designed to provide enhanced mechanical properties and resistance to atmospheric corrosion. When exposed to outdoor elements, weathering steels naturally develop a protective patina layer, which is produced by the particular distribution and concentration of alloying elements within it. The patina regenerates continuously when subjected to weather to guard against corrosion.  

ASTM specifications for weathering steels

Weathering steels are a family of ASTM specifications and several trademarked specifications exhibiting similar corrosion-resistant properties. The ASTM specifications include A588, A242, A606-4, A847, A871-65 and A709-50W. The primary trademarked product is Cor-ten®, which is United States Steel Corporation (USS) trade name for an atmospheric corrosion resistant steel.  The selection of a particular ASTM weathering steel specification is dependent on the type of product desired. For example, ASTM A588 covers structural shapes, plate, and bar while ASTM A242 covers steel plate through one-half inch in thickness. 

Contact Central Steel Service For High Strength Weathering Steels

Weathering steel is available in various grades, specifications and shapes and can be used in a variety of applications. Some types of weathering steel are better suited for certain applications, so knowing the right type to use for your application can save time and money on additional processing. 

Established in 1981, Central Steel Service, Inc. specializes in the distribution of High Strength Weathering, High Strength and Abrasion Resistant Steel products. Contact an experienced sales representative, and we can help you determine the best type of steel for your project.