Blueing


Also found in: Dictionary, Thesaurus, Medical.

blueing

[′blü·iŋ]
(metallurgy)

Blueing

 

the process of obtaining a layer of iron oxides (Fe304 and others) 1-10 microns thick on the surface of components made of carbon or low-alloy steel and cast iron. The coating has a fine crystalline, microporous structure. Blueing is used for decorative finishing. The protective properties of the layers formed during blueing are weak; therefore, after blueing the components are covered with grease to increase their corrosion resistance.

There are various methods of blueing: alkaline blueing, in alkaline solutions with oxidizers at temperatures of 135°-150° C; acid blueing, in acidic solutions by chemical or electrochemical means; and thermal blueing, which is the oxidation of steel at high temperatures—in an atmosphere of superheated water vapor at 200°-480° C, in vapors of an ammonia-alcohol mixture at 520°-880° C, in melted salts at 400°-600° C, or in an air atmosphere at 310CM50° C after first covering the surface of the components with a thin layer of asphalt or oil varnish.

REFERENCES

Vainer, la. V., and M. A. Dasoian. Tekhnologiia elektrokhimicheskikh pokrytii. Moscow-Leningrad, 1962.
Bakhvalov, G. T. Zashchita metallov ot korrozii. Moscow, 1964.

V. V. BONDAREV

References in periodicals archive ?
And finally, before you buy a mop head hydrangea, ask in the garden centre if it will respond to blueing powder.
Fluorescent Whitening: Krais, a German chemist, discovered that blueing can be affected not only with a blue dye but with colourless substance which gave a fluorescent in ultra violet light.
Looking at the now-scratched wood and the shiny spot around the crown where the blueing had worn off, I felt that the rifle deserved better.
Power buffing wheels and modern hot salt blueing can result in a rifle that shines like new but carries ugly, buffed out lettering, dished screw holes and an octagonal barrel full of unsightly dips and waves.
It is marked "Brevette 1915" and has about 80 percent of its blueing.
Blueing is done on-site, but plating and Baercoat[R], (a durable, self-lubricating finish) are done by vendors.
The blueing is decent, and the grips are checkered wood.
Blueing gives yet another look into Birch's vision.
I still love fancy walnut and rich blueing, but my Alaskan rifle is synthetic-stocked with a Teflon coating on the metal parts.
It shows very little wear, with only slight loss of blueing on each side and at the very end of the barrel.