What is the heat treatment of Inconel 600?
Description
Alloy 600 is a nonmagnetic, nickel-based high temperature alloy possessing an excellent combination of high strength, hot and cold workability, and resistance to ordinary form of corrosion.
This alloy also displays good heat resistance and freedom from aging or stress corrosion throughout the annealed to heavily cold worked condition range.
Applications
Some typical applications are:
Barge and tank truck liners
Carburizing atmospheres
Ethylene dichloride crackers
Furnace trays, mufflers, hangers
Gasoline stabilizer production
MgCl2 evaporates
Phenol condensers
Soap manufacture
Titanium dioxide
Vegetable and fatty acid vessels
Corrosion Resistance
The high chromium content of alloy 600 raises its oxidation resistance considerably above that of pure nickel, while its high nickel content provides good corrosion resistance under reducing conditions.
This alloy exhibits high levels of resistance to stress and salt water, exhaust gases, and most organic acids and compounds.
Heat Treatment
Alloy 600 is not an age hardening alloy; cold working is the only available means of hardening. Softening by annealing begins at about 1600°F (871°C), and is reasonably complete after 10 to 15 minutes of heating at 1800°F (982°C). Above this temperature, grain growth may be objectionable, although very brief heating at 1900°F will cause complete softening without undue grain growth. Since the rate of cooling has no effect on the softening, the material may be water quenched or air cooled.
Machinability
Hot Working/Forging
A low sulfur reducing furnace atmosphere should be used for forging. Major hot working should be performed between 2300/1850°F, while light working may continue at temperatures as low as 1600°F. Hot working should not be attempted due to lower ductility in the 1600/1200°F range.
Machinability
600 alloy is machinable in both the hot worked and annealed conditions. Due to the high heat generated in machining this alloy, high speed steel, cast nonferrous, or carbide tools should be used. Tools should be kept sharp.
Lathe turning speeds are 35/45 sfm (0.18/0.23 m/s) with high speed and nonferrous tools; 100/175 sfm (0.51/0.89 m/s) with carbide tools. (This data should be used as a guide only for initial machine settings. The figures used are averages. On some jobs, the nature of the parts may require adjustment of speeds and feeds.)
Sulfur-containing oils should be used as lubricants but should be completely removed before machined parts are exposed to high temperatures (such as welding).
Cold Working
For higher properties, Alloy 600 can be cold worked to temperatures below 1200°F (649°C).
Welding
Alloy 600 can be joined by common welding, brazing, and soldering processes.
