The corrosion behaviour of nickel pipe used for falling-film evaporator was studied by metallography, SEM, EPMA, XRD and electrochemical techniques etc. And a proposal of using electroless nickel-phosphorus amorphous alloy coating to increase the service life time of pure nickel pipe was examined. The results show that the corrosion products consist of NiO with 3-4% Cl, which reveal that the impurity NaClO_3 in raw caustic solution may be the most important factor resposible for the fast corrosion of the nickel pipe.
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