ER308 is a type of stainless steel welding wire classified under the American Welding Society (AWS) A5.9/A5.9M:2012 specification. The ER308 designation indicates specific characteristics and properties of the welding filler metal. Here are the key specifications for ER308:

Classification:

AWS A5.9/A5.9M:2012 – This standard provides guidelines for the classification of stainless steel welding and filler metals.
Designation:

ER308 – The “ER” prefix indicates it is an electrode or filler metal, and “308” signifies the specific alloy composition.
Alloy Composition:

ER308 contains chromium (around 19-21%), nickel (around 9-11%), and a maximum of 0.08% carbon. It is designed for welding austenitic stainless steels of the 18-8 type, such as 304 and 304L.
Welding Positions:

ER308 wire is versatile and suitable for welding in various positions, including flat, horizontal, vertical, and overhead.
Shielding Gas:

Commonly used with the shielding gas of Argon, or a mixture of Argon and CO2, depending on the specific welding application.
Applications:

ER308 is widely used for welding similar alloys in the chemical, food processing, pharmaceutical, and petrochemical industries. It is suitable for joining stainless steels for structural and general corrosion-resistant purposes.
Diameter Range:

Available in various diameters, commonly ranging from 0.8 mm to 2.4 mm, to accommodate different welding processes and applications.
Welding Processes:

ER308 can be used in Gas Tungsten Arc Welding (GTAW or TIG) and Gas Metal Arc Welding (GMAW or MIG/MAG) processes.
It’s important to refer to the specific manufacturer’s data sheet for the ER308 welding wire being used, as different manufacturers may slightly vary in their formulations and recommended welding parameters. Additionally, adherence to proper welding procedures and industry guidelines is crucial for achieving quality welds.

Chemical Composition of ER308 Stainless Steel

The chemical composition of ER308 stainless steel welding wire is designed to meet certain specifications, particularly for welding austenitic stainless steels of the 18-8 type, such as 304 and 304L. The typical chemical composition (wt%) for ER308 is as follows:

Carbon (C): Maximum 0.08%
Manganese (Mn): 1.00 – 2.50%
Phosphorus (P): Maximum 0.045%
Sulfur (S): Maximum 0.030%
Silicon (Si): 0.30 – 0.65%
Chromium (Cr): 18.0 – 21.0%
Nickel (Ni): 9.0 – 11.0%
Molybdenum (Mo): Maximum 0.75%
Iron (Fe): Balance

These specifications are in accordance with the AWS A5.9/A5.9M:2012 standard for welding filler metals, specifically for austenitic stainless steels. The controlled composition ensures that the welding wire provides good corrosion resistance, strength, and other mechanical properties when used in welding applications. It’s important to note that the actual composition may vary slightly depending on the specific manufacturer. Always refer to the manufacturer’s data sheet for precise information on the chemical composition of the ER308 welding wire you are using.