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Three processes developed for the nickel coating of steel using slurries of nickel powders are outlined. The processes described vary at the initial stage of consolidation and involve (1) warm compaction, (2) hot compaction, (3) sintering. The final requirements of the coated product are ductility and corrosion-resistance; the latter property being the most difficult to achieve and requiring specific controls at various stages. The stages discussed are steel type and pretreatment, slurry composition and method of application, thermal treatments, and rolling parameters.With the controls recommended at each stage, the three processes will provide corrosion resistance equivalent to that of electroplated materials as judged fromaccelerated corrosion tests and field trials.One of the processes was scaled up to pilot-line proportions, operating continuously on 1 tonne coils 300 mm (12 in) wide.

Superior corrosion resistivity of nickel-chromium coating can be presumed to some extent from the electrochemical investigation previously reported.A series of corrosion tests, including outdoor exposure at seaside, was carried out to study the performance of copper-nickel-chromium and double nickel-chromium plated steel test pannels.As a result, the following conclusions were obtained:(1) In the salt spray and sulfur dioxide test, any superiority of the double nickel-chromium coatings to the copper-nickel-chromium coating was not observed.(2) In the Korrodkote and CASS test, the performance of the former was excellent, regardless of the thickness. On the other hand, the latter was rapidly deteriorated.(3) In the outdoor exposure at seaside, the former with total thickness of 30μ was excellent, but the former with total thickness of 20μ was often inferior to the latter with total thickness of 40μ.(4) As the proportion of semibright nickel in a double nickel coating is increased, its durability in the outdoor exposure increases. Contrary to this, quite reversed phenomenon was observed in the Korrodkote and CASS tests.

SummaryThe deposition of an attractive nickel coating from a reliable easily maintained solution with an all-liquid brightener system is described. It is considered that the versatility of the final product has proved more than worth the little extra plant required in this system for temperature adjustments. The finish has a characteristic sheen which is attractive and recognizable. The method of attaining it has novel features and is interesting both in theory and practice. Its applications in the decorative field of finishing are extremely wide. The finish is also of considerable importance in satisfying the new safety regulations for automobile components.

Harnstoff ubt auf die Stromausbeute eines Nickelbades einen sehr nachteiligen Einflus aus, da diese bis auf weniger als 50% herabgesetzt wird. Es treten in Gegenwart von Harnstoff grosere Polarisationen auf, die durch eine Temperatur- und Stromdichteerhohung nur teilweise vermindert werden konnen. Ein Harnstoff-Zusatz gestattet jedoch bei niedrigen PH-Werten des Bades auch bei verhaltnismasig niedrigen Nickelsalz-Konzentrationen selbst bei hohen Stromdichten von 20 A/dm2 noch gute Nickel-Niederschlage abzuscheiden. Der Glanz des Nickeluberzuges wird durch Harnstoff erheblich verbessert. The influence of urea on the electrolytic deposition of nickel Urea has a highly detrimental effect on the current yield of a nickel bath as the yield is reduced to less than 50 per cent. The presence of urea gives rise to higher polarisations which can be only partially reduced by increasing the temperature and current density. With a urea addition, however, it is possible, at low pH values of the bath, to obtain good nickel deposits even with comparatively low nickel salt concentrations and even with high current densities of 20 amps/dm2. The brightness of the nickel coating is considerably improved by urea.

Tantalum may be prepared for electroplating with nickel by a cathodic pickle in a mixture of hydrofluoric and hydrochloric acids in methanol. The nickel coating was formed in two stages. Heat treat...

A requiremcnt often encountered in electron tube developmental work is the joining of copper to stainless steel. The usual methods of pcrforming such brazes require that a protective nickel coating first be applied to the stain equent brazing operation be carried out in dry hydrogen. An alternative method not requiring hydrogen, prior to nickel plating, or fluxing is described. This new technique has been applied only to the formation of butt joints. (A.C.)

THE reducing properties of hypophosphite for metal ions have been known since 1844, but not until 1946 did Brenner successfully apply the principle to produce a practical plating method. In the following year, the engineering department of General American Transportation Corporation wished to obtain a cheaper tank‐car plating than the usual one of nickel‐clad construction. The Brenner method was considered, but proved unsuitable, and a process was developed which is now known by the trade mark Kanigen.

The fatigue life of nickel-plated copper depends upon the thickness of the nickel coating. Increases in life from 150 to 450 percent were obtained by increasing the thickness of the nickel from 0.0001 to 0.00025 in. (0.00254 to 0.00635 mm). A further increase in thickness to 0.005 in. (0.0127 mm) resulted in an increase in life of 200 percent. Interrupting the current during electroplating produces interfaces within the coating and increases the fatigue life for a given thickness. Increases in life of 110 percent were obtained by applying a 0.0005-in. thick coating in five layers, rather than in a single layer.

The instrument and its various parts are so well shown in the illustrations that no further description is necessary. It is a more powerful instrument than the ordinary tonsil snare and does not get out of order like many others. It is simple in application, can be used a number of times without requiring a new wire, and, if properly adjusted, the wire cannot slip. It should be manipulated by a sort of forearm and wrist movement, instead of by the fingers, in closing it, so that the barrel will not be thrown out of line. It is made of solid brass with a heavy nickel coating. Number 7 or 8 piano wire should be used. I have used the instrument a number of times with excellent results. It is made by the O'Brien Worthen Co., Frisco Building, St. Louis. 220 Metropolitan Building.