A nickel-chromium alloy with good oxidation resistance at higher temperatures. With good resistance in carburizing and chloride containing environments.

Alloy 600 is a nickel-chromium alloy designed for use from cryogenic to elevated temperatures in the range of 2000 deg F(1093 °C). The high nickel content of the alloy enables it to retain considerable resistance under reducing conditions and makes it resistant to corrosion by a number of organic and inorganic compounds. The nickel content gives it excellent resistance to chloride-ion stress-corrosion cracking and also provides excellent resistance to alkaline solutions.

Its chromium content gives the alloy resistance to sulfur compounds and various oxidizing environments. The chromium content of the alloy makes it superior to commercially pure nickel under oxidizing conditions. In strong oxidizing solutions like hot, concentrated nitric acid, 600 has poor resistance. Alloy 600 is relatively un-attacked by the majority of neutral and alkaline salt solutions and is used in some caustic environments. The alloy resists steam and mixtures of steam, air and carbon dioxide.

Alloy 600 is non-magnetic, has excellent mechanical properties and a combination of high strength and good workability and is readily weldable. Alloy 600 exhibits cold forming characteristics normally associated with chromium-nickel stainless steels.

Typical corrosion applications include titanium dioxide production (chloride route), perchlorethylene syntheses, vinyl chloride monomer (VCM), and magnesium chloride. Alloy 600 is used in chemical and food processing, heat treating, phenol condensers, soap manufacture, vegetable and fatty acid vessels and many more.

Characteristics

• Resistant to a wide range of corrosive media. The chromium content gives better resistance than Alloy 200 and 201 under oxidizing conditions, at the same time the high nickel gives good resistance to reducing conditions.

• Virtually immune to chlorine ion stress corrosion cracking.

• Demonstrates adequate resistance to organic acids such as acetic, formic and stearic.

• Excellent resistance to high purity water used in primary and secondary circuits of pressurized nuclear reactors.

• Little or no attack occurs at room and elevated temperatures in dry gases, such as chlorine or hydrogen chloride. At temperatures up to 550 °C in these media, this alloy has been shown to be one of the most resistant of the common alloys.

• At elevated temperatures the annealed and solution annealed alloy shows good resistance to scaling and has high strength.

• The alloy also resists ammonia bearing atmospheres, as well as nitrogen and carburizing gases.

• Under alternating oxidizing and reducing conditions the alloy may suffer from selective oxidation.

Applications

• Thermocouple sheaths.

• Ethylene dichloride (EDC) cracking tubes.

• Conversion of uranium dioxide to tetrafluoride in contact with hydrofluoric acid. Production of caustic alkalis particularly in the presence of sulfur compounds.

• Reactor vessels and heat exchanger tubing used in the production of vinyl chloride.

• Process equipment used in the production of chlorinated and fluorinated hydrocarbons.

• In nuclear reactors uses are for such components as control rod inlet stub tubes, reactor vessel components and seals, steam dryers and d separators in boiling water reactors. In pressurized water reactors it is used for control rod guide tubes and steam generator baffle plates etc. Furnace retort seals, fans and fixtures.

• Roller hearths and radiant tubes, in carbon nitriding processes especially.