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Because graphite has a series of excellent characteristics mentioned above, as a heating element of vacuum resistance furnace, it is more and more popular in the heat treatment industry and is increasingly widely used in high temperature resistance furnace.

Graphite has the characteristics of high temperature resistance, small thermal expansion and strong thermal shock resistance. At normal temperature, the strength of graphite is worse than that of metal, but its mechanical strength increases with the increase of temperature below 2500C, and is best at 1700 ~ 1800C, even exceeding all oxides and metals. Graphite material has high melting point and low vapor pressure. The atmosphere in the vacuum furnace will contain low concentration of carbon, which will react with O2 and H2O vapor molecules in the residual gas to produce purification effect. Even under low vacuum, the workpiece to be processed can obtain bright surface state, greatly simplifying the vacuum system and reducing the cost, which is incomparable to any metal electric heater.