Protective value of nickel and chromium plating on steel

Blum, William; Strausser, P.W.C.; Brenner, Abner

doi:10.6028/jres.013.024

Cited by 14 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the first heating to 500° C the sample contracted considerably, probably with an evolution of hydrogen. 2 At 500° C, the sample was 0.7 percent shorter than the initial length before heating. On cooling the sample to room temperatme, the observations appeared to lie on a smooth cmve.…”

Section: Resultsmentioning

confidence: 97%

“…From the coefficients of expansion obtained in the tests in which the expansion curves were smooth and free from irregularities (sample 1359A on tests 2 to 10, inclusive, and sample 13281 on tests 4 and 5), the following empirical equation was derived by the method of least squares: a,= (5.88+0.01548t-0.00001163t 2 ) 10-6 , (1) where at represents the instantaneous coefficient of expansion or the rate of expansion at any temperature, t, between -75 0 and +650 0 C.…”

Section: Resultsmentioning

confidence: 99%

“…(1) (2) where at represents the instantaneous coefficient of expansion or rate of expansion at any temperature, t, between -75 0 and +650 0 OJ Lo represents the length at 0 0 0; and L t the length at any temperature, t, between -100 0 and +700° O. Figure 4 and table 3 give coefficients of expansion computed from eq 1 and 2, and show comparisons with data from other observers.…”

Section: Discussionmentioning

confidence: 97%

“…The porosity of new deposits of electroplated chromium coatings has been observed to increase for several weeks or on heating [1],1 and the development of cracks in chromium plating during atmospheric exposure at ordinary temperatures has been discussed by several observers [2,3]. Determinations of the linear thermal expansion of electrolytic chromium therefore appeared to ,be desirable for a possible explanation of the behavior of chromium platings, particularly when heated.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Thermal expansion of electrolytic chromium

Hidnert¹

1941

J. RES. NATL. BUR. STAN.

View full text Add to dashboard Cite

The linear thermal expallsion of two samples of electrolytic chromium was invest igated at various temperatures between -105 0 and +715 0 C. During the first heating or heatings, when hydrogen presumably was being evolved, the samples contracted in an irregular manner . After a few heatings, however, the irregularities disappeared and smooth expansion curves were obtained. It appears also, that the linear thermal expansion of electrolytic chromium, when it is first heated, may be affected by variables such as the temperature, time and rate of h eating, previous treatment, etc. The following equations were derived for the length, L" at any temperature, t, between -100 0 and +700 0 C, and for the coefficient of expansion, a" at any temperature, t, between -75 0 and + 650 0 C:The density of the sample of electrolytic chromium cont aining 99.3 percent of chromium increased 2.4 percent and the volume decreased 2.3 percent, after three cycles of heating to 500 0 C and cooling to room temperature. The length decreased 1.1 percent.

show abstract

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 97%

mentioning

confidence: 99%

See 2 more Smart Citations

Thermal expansion of electrolytic chromium

Hidnert¹

1941

J. RES. NATL. BUR. STAN.

View full text Add to dashboard Cite

show abstract

“…The results obtained with nickel and chromium finishes have been published [1], [2]. 2 The purpose of this paper is to describe and discuss the results obtained in about 3.5 years' atmospheric exposure of zinc and cadmium coatings, and of a few deposits consisting of alloys of zinc and cadmium.…”

Section: Introductionmentioning

confidence: 99%

Corrosion-protective value of electrodeposited zinc and cadmium coatings on steel

Blum¹,

Strausser²,

Brenner³

1936

J. RES. NATL. BUR. STAN.

Self Cite

View full text Add to dashboard Cite

Atmospheric exposure of plated specimens in six locations showed that in a rural or purely marine climate, both zinc and cadmium coatings furnished better protection against the corrosion of steel than did nickel or chromium coatings of the same thickness, although the zinc and cadmium rapidly lost their luster. In an industrial atmosphere, where sulphurous and sulphuric acids are present, both zinc and cadmium were attacked rather rapidly, and the life was about proportional to the thickness . Under these conditions the cadmium coatings failed in about two-thirds of the time required for failure of zinc coatings of the same thickness. Zinc-cadmium alloys containing about 10 percent of cadmium were superior to either zinc or cadmium. Variations in the conditions selected for depositing the coatings did not have a marked effect on their protective value. Hot-dipped zinc coatings gave about the same protection as plated zinc coatings of the same thickness.In accelerated t ests, Buch as the salt spray or intermittent immersion in a solution of sodium chloride, the time required for failure of a zinc coating is about proportional to its thickness. Cadmium coatings last much longer than those of zinc in a salt spray, which is not, therefore, a true measure of their relative value in an industrial atmosphere.The protective value of a zinc or cadmium coating depends principally upon its minimum thickness, which can be determined by dropping tests, microscopic measurements, and the chord method.

show abstract

Electrodeposition of Chromium

Mandich¹,

Snyder²

2010

Modern Electroplating

View full text Add to dashboard Cite

Electroplated chromium deposits rank among the most important plated metals and are used almost exclusively as the final deposit on parts. Without the physical properties offered by electroplated chromium deposits, the service life of most parts would be much shorter due to wear, corrosion, and the like. Parts would have to be replaced or repaired more frequently, or they would have to be made from more expensive materials, thus wasting valuable resources.The thickness of electroplated chromium deposits falls into two classifications: decorative and functional. Decorative deposits are usually under 0.80 mm in thickness. They offer a pleasing, reflective appearance while also providing corrosion resistance, lubricity, and durability. Decorative chromium deposits are typically plated over nickel but are occasionally plated directly over the substrate of the part.Functional ''hard chrome'' deposits have a thickness customarily greater than 0.80 mm and are used for industrial, not decorative, applications. In contrast to decorative deposits, functional chromium is usually plated directly on the substrate and only occasionally over other electrodeposits, such as nickel. Industrial coatings take advantage of the special properties of chromium, including resistance to heat, hardness, wear, corrosion, and erosion, and a low coefficient of friction. Even though it has nothing to do with performance, many users want their functional chromium deposits also to be decorative in appearance. Functional deposits are also used on parts such as cutting tools and strip steel and are even thinner than decorative deposits.The most common and oldest commercial type of chromium process utilizes hexavalent chromium (Cr 6 þ ) in an aqueous solution containing one or more catalysts. The

show abstract

Protective value of nickel and chromium plating on steel

Cited by 14 publications

References 0 publications

Thermal expansion of electrolytic chromium

Thermal expansion of electrolytic chromium

Corrosion-protective value of electrodeposited zinc and cadmium coatings on steel

Electrodeposition of Chromium

Contact Info

Product

Resources

About