Blackening


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Blackening

 

a type of oxide coating for iron and steel products, used for corrosion protection and for decorative purposes. The most common method of blackening is to immerse the products in a concentrated alkaline solution containing sodium nitrate or sodium nitrite as an oxidizer. As the concentration of the alkali is increased (other conditions being equal), the thickness of the oxide film also increases. A thin coating (20 to 40 angstroms) does not alter the external appearance of the surface nor does it provide practical protection for the metal against corrosion. Thick coatings (2.5 micrometers), which are black or grayish black, have poor mechanical strength. The best thickness is 0.6 to 0.8 micrometer. Blackening is a special case of blueing.

References in periodicals archive ?
It's imperative that you dredge your seafood through a puddle of melted, unsalted, butter, before you cover it with the blackening spice and put it into the almost red-hot pan.
For now they plough on and more than 350 dates into the never-ending Blackening jaunt it's not as if Flynn looks like a man in need of a breather.
The album gave the band their highest chart position in the UK, number 16, and has become a metalmust-have, but after three years of touring it, Machine Head will pack up The Blackening and return to the studio in April.
In other words, these thrash-bred guys from the Bay Area got their epic on for "The Blackening," making the sort of move into big sounds that their forebears Metallica did a generation earlier with ".
Working with Command, Birchwood Casey installed a seven-tank, 100 gal in-house blackening line that reduced turnaround time from three days to 34 minutes.
BLACKENING SPICE: Combine 2 tablespoons kosher salt, 2 tablespoons sugar, 1 tablespoons freshly ground pepper, 1 tablespoon plus 1 teaspoon cayenne pepper, 2 tablespoons paprika, 1 tablespoon dried thyme and 1 tablespoon dried oregano in a small bowl.
Considered a major insult, blackening her face isn't nearly as extreme as the call for her death by hardliners in 1994.
Blackening somebody's face with shoe polish or soot is considered a grave insult in India.
Blackening someone's face with soot or shoe polish is a grave insult in India and The Raza Academy, that offered the reward, also organised a protest in which 100 hardline Muslims carried banners calling for the Indian-born author to be killed.
It explores them first as images, Classically-clad in the eighteenth century, and then as functional structures, blackening the industrial skyline.