63092400 - Bonarc ER309L Stainless Steel TIG Rod - 2.4mm (5kg Tube)

Technical Overview of Bonarc ER309L TIG Filler Metal

The Bonarc ER309L is a premium quality austenitic stainless steel TIG welding rod designed to meet AWS A5.9 specifications. This 2.4mm filler metal is specifically formulated with a higher chromium (23-25%) and nickel (12-14%) content compared to standard 304/308 grades. This alloy composition provides exceptional corrosion resistance and oxidation resistance at elevated temperatures. The 'L' designation indicates a low carbon content (maximum 0.03%), which is critical for preventing sensitization and intergranular corrosion in the heat-affected zone (HAZ) during multi-pass welding operations.

Primarily engineered for welding base metals of similar composition (AISI 309/309S), this rod is the industry standard for joining dissimilar steels, such as austenitic stainless steel to carbon or low-alloy steels. It is also extensively used for applying buffer layers on carbon steel prior to cladding with 308 or 316 grades. The metallurgical structure typically contains a controlled amount of ferrite to minimize susceptibility to hot cracking, a common issue when welding fully austenitic structures. The 2.4mm diameter offers a balanced deposition rate suitable for medium-gauge fabrication and root passes in pipe welding.

Packaged in a durable 5kg tube, these rods are protected from environmental contaminants, ensuring consistent weld quality. The rods are designed for use with DCEN (Direct Current Electrode Negative) polarity and 100% Argon shielding gas to produce clean, defect-free welds with excellent mechanical properties.