EX3470000000620TL0 - Exocor ER347 Stainless TIG Rod 1/16" (10lb Tube)

Technical Overview of Exocor Executive ER347

The Exocor Executive ER347 is a premium stainless steel TIG welding rod designed specifically for joining base metals of similar composition, such as AISI 347 and 321. This filler metal is distinguished by the addition of Niobium (also known as Columbium), which acts as a stabilizing element. In austenitic stainless steels, exposure to temperatures between 425°C and 800°C can lead to chromium carbide precipitation at the grain boundaries, significantly reducing corrosion resistance. The Niobium in ER347 has a stronger affinity for carbon than chromium does, effectively tying up the carbon and preventing the depletion of chromium. This mechanism ensures the weld metal retains exceptional resistance to intergranular corrosion.

Metallurgically, this rod is formulated to provide a microstructure that balances austenite with a controlled ferrite number, minimizing the risk of hot cracking during solidification. It is particularly suited for applications involving high service temperatures where creep strength is a critical factor. The presence of Tantalum (Ta) alongside Niobium is standard in this alloy class and contributes equally to the stabilization and high-temperature mechanical properties. This rod meets AWS A5.9 classifications and is manufactured to rigorous standards to ensure consistent chemistry and diameter tolerance.

Engineers and metallurgists specify ER347 for fabrication involving pressure vessels, chemical storage tanks, and piping systems that process corrosive media at elevated temperatures. It is also the preferred choice when the weldment cannot be annealed after welding. The rod requires 100% Argon shielding gas and is operated on DCEN (Direct Current Electrode Negative) polarity to achieve deep penetration and a stable arc characteristic.