Properties of nickel crucibles
NickelCommercially pure or low-alloy nickel has characteristics that are useful in several
fields, notably chemical processing. Nickel is highly resistant to various reducing
chemicals and is unexcelled in resistance to caustic alkalis. Nickel 201 is acommercially pure nickel with high thermal conductivity.

Nickel 201
Nickel 201 is commercially pure (99.6%) wrought nickel and a low carbon version ofNickel 200. It has good mechanical properties and excellent resistance to many
corrosive environments. Other useful features: high thermal and electricalconductivities, low gas content and low vapor pressure. The corrosion resistancemakes it particularly useful for maintaining product purity in the handling of foods,liquids, synthetic fibers, and caustic alkali's.

High-temperature and Corrosion Resistance properties
Nickel 201 has the excellent corrosion resistance characteristic of Nickel 200.
Because it is a low-carbon material (0.02% max.), Nickel 201 is not subject toembrittlement by intergranularly precipitated carbon or graphite when held attemperatures of 315° to 760°C for extended times, provided carbonaceous materialsare not in contact with it. It is, therefore, preferred to Nickel 200 in all cases wheretemperatures exceed 315°C. Nickel 201 is ideal for laboratory crucibles which arecapable of withstanding oxidizing furnace atmospheres up to 1100°C. Above 300°C
its mechanical properties change: tensile strength falls, elongation grows making forexample a crucible more malleable when handling or when heated by a direct flame.
This can lead to a change in the profile/shape of a crucible. The material is subject tointergranular embrittlement by sulphur compounds at temperatures above 315°C.
Water
The resistance of Nickel 201 to corrosion by distilled and natural waters is excellent
since resistant to water containing hydrogen sulphide or carbon dioxide. Nickel 201
gives excellent service in seawater.

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AcidsSulphuric
Nickel 201 can be used with Sulphuric acid at low or moderate temperatures.

Hydrochloric
According to the data available, Nickel 201 may be used in hydrochloric acid inconcentrations up to 30%, at room temperature. Increasing temperature will
accelerate corrosion. If oxidizing salts are present in any but very small amounts,corrosion will be increased. At less than 0.5% concentration, the material can beused satisfactorily up to 150°-205°C.

Hydrofluoric
Nickel 201 has excellent resistance to anhydrous hydrofluoric acid even at elevatedtemperatures. In aqueous solutions, however, service is usually limited to below
80°C. Even at room temperature, 60-65% commercial-grade acid has been found toseverely corrode Nickel 201.

Phosphoric
Nickel 201 is resistant to phosphoric acid.

NitricNickel 201 should not be used in nitric acid.

Organic
In general, Nickel 201 has excellent resistance to organic acids of all concentrations.

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Alkali's
The outstanding corrosion resistance characteristic of Nickel 201 is its resistance tocaustic soda and other Alkali's. (Ammonium hydroxide is an exception. Nickel 201 is
not attacked by anhydrous ammonia or ammonium hydroxide in concentrations of1%. Stronger concentrations can cause rapid attack.)
In caustic soda, Nickel 201 has excellent resistance to all concentrations up to andincluding the molten state. Below 50%, rates are negligible, even in boiling solutions.
As concentration and temperature increase, corrosion rates increase very slowly. The
chief factor contributing to the outstanding performance of Nickel 201 in highly
concentrated caustic soda is a black protective film that forms during exposure. Thisfilm – nickel oxide – results in a marked decrease in corrosion rates over longexposure under most conditions. Because the presence of chlorates in caustic
increases corrosion rates significantly, every effort should be made to remove as
much of them as possible. Results of tests in sodium hydroxide solutions of varying
concentrations produces a typical thin black oxide film, found on some of the samples
in the tests at boiling temperature. Oxidizable sulphur compounds are also harmful,but, by adding sodium peroxide to change them to sulfates, their effect can beminimized.

Salts
The metal is not subject to stress-corrosion cracking in any of the chloride salts andhas excellent resistance to all of the non-oxidizing halides. Oxidizing acid chlorides
such as ferric, cupric and mercuric are very corrosive and should be used in low
concentrations. Stannic chloride is less strongly oxidizing, and dilute solutions atatmospheric temperature are resisted. The maximum safe limit in oxidizing alkaline
chlorides is 500 ppm available chlorine for continuous exposure. In bleaching,sodium silicate (1.4 specific gravity) can be used as an inhibitor to corrosion; as little
as 0.5ml/liter of bleach has been found to be effective. Some very reactive andcorrosive chlorides – phosphorus oxychloride, phosphorus trichloride, nitrosylchloride, benzyl chloride and benzoyl chloride – are commonly contained in Nickel
201. It has excellent resistance to neutral and alkaline salt solutions.

Fluorine and chlorine
In comparison with other commercial metals and alloys, Nickel 201 has outstanding
resistance to dry fluorine. Nickel 201 is the most practical for service in chlorine orhydrogen chloride at elevated temperatures.

Bochem Instrumente GmbH *** www.bochem.com *** info@bochem.deChemical content of Nickel 200

Nickel and Cobalt
CopperIron
Carbon
SiliconManganese
Magnesium
SulphurOthersNickel und Cobalt
Kupfer
Eisen
KohlenstoffSilizium
ManganMagnesium
Schwefel
Andere99,709 %0,01 %
0,03 %
0,042 %
0,03 %
0,087 %
0,09 %
0,001 %
0,001 %

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