Pollutant-free blackening salt bath



The technique and the salt are R&D by Gnail.

Blackening temperature and time: 350~400°C about 0.5~1 hour
Colour after heattreatment: deep black with fine and uniform surface
24 working hours consumption rate: no

The surface of workpiece heattreated is black with a compact  Fe3O4  layer and gets no aglow appearance( Fe2O3.H2O. The liquid blackening salt is stable, no aging, no volatilization, no irritative gas,  etc. The composition of liquid pollutant-free blackening salt need not be adjusted. Temper and blacking can be fulfiled once if the temperature of temper is proper. So it is more efficientcy than traditional technique.

       *It is used only for steel and iron

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