INCONEL alloy G-3 (UNS N06985/W. Nr. 2.4619) is a nickel-chromium-iron alloy with additions of molybdenum and copper. Some of the minor elements are controlled to yield increased resistance to heat-affected-zone (HAZ) corrosion and improved weldability. Alloy G-3 has excellent corrosion resistance to oxidizing chemicals and atmospheres. It is also resistant to reducing chemicals because of its nickel and copper contents. Nickel also provides the alloy with exceptional stress-corrosion-cracking resistance in chloride-containing environments. The high molybdenum provides very good resistance to pitting and crevice corrosion. The low carbon helps prevent sensitization, giving the alloy resistance to intergranular corrosion.

INCONEL alloy G-3 is particularly suitable for handling reducing acids such as phosphoric and sulfuric. It is used in flue gas desulfurization systems (scrubbers), especially in quencher, damper, and outlet ducting areas. It can be used in other air pollution control systems in the chemical and pulp and paper industries. It is a good candidate for evaporators, heat-exchangers, tank liners, and other equipment in phosphoric acid manufacturing plants.

Today's exploration for oil and gas leads to a range of highly corrosive environments that, in turn, require a range of corrosion-resistant high nickel content alloys. INCONEL® alloy G-3 is one of these alloys, providing an excellent combination of mechanical properties and strength. This alloy has been used extensively as OCTG (Oil Country Tubular Goods) in hot, sour environments.