EVO SP's Custom Shop Special is finished in KimPro charcoal gray on the frame and black Ferritic
Nitro Carburizing (FNC) on the slide.
nitrocarburizing (sometimes abbreviated FNC) is a case hardening processes that diffuses nitrogen and carbon into ferrous metals at sub-critical temperatures during a salt bath.
Founded in 1946, the company pioneered advancements in ferritic
nitrocarburizing with the development of the H&M Blacknitride+[TM] process.
Atmosphere Annealing has more than 400,000 tons of installed heat treating capacity including annealing, ferritic
nitrocarburizing, normalising, and quench and temper processing for various industries, including automotive, light and heavy truck, agriculture, and energy.
I'm betting that these cases are made from a ferritic
stainless steel, which doesn't contain nickel at all.
Due to such design of the tool and the use of optimal parameters, the VCH provides the formation of a ferritic
class UFGS (Figures 2 and 3) with a grain size on the surface up to 190 nm, a high density of dislocations, and microstresses in the lattice (Figure 4).
General corrosion is attributed to the preferential dissolution of the ferritic
phase and it often manifests by a cementite scale ([Fe.sub.3]C) formation.
* Solution strengthened ferritic
ductile iron--strain life fatigue database.