These steels are usually tempered above 572F (300C), which lowers the soluble carbon in ferrite to that being in equilibrium with cementite
(Stage III tempering) or with the alloy carbide formed during secondary hardening.
In the sub-critical zone, some of the base metal martensite phase is tempered and some of the remaining austenite phase is converted to ferrite and cementite
. In the inter-critical area, the temperature is much more limited due to [Ac.sub.1] and [Ac.sub.3] critical temperatures.
Some eight officials of the Italy-based Cooperative Moratoria and Cementite
di Ravenna (CMC) company that owned the contract of the Melamchi Drinking Water Project were arrested while they were preparing to leave Nepal by leaving works at the national pride project incomplete.
, on tempering process of steels which contained chrome and chrome-molybdenum at 1246oC, orthorhombic cementite
contained hexagonal Mo2C particles in the ferrite base were observed for chrome steels and chromemolybdenum steels respectively.
The high-hardness lamellar cementite
of the C70S6 reduces its machinability.
Moreover, sparse precipitates of carbide phases (mostly cementite
) were observed; see Figure 4(a).
Bhowmik, "Electropulse-induced cementite
nanoparticle formation in deformed pearlitic steels," Journal of Materials Science, vol.
There are no cementite
lines on X-ray patterns (Figure 3), which agrees well with [14, 15] on the decomposition of cementite
as a result of cold plastic deformation.
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.
Damascus saber blades contained carbon nanotubes and cementite
nanowires--an ultra-high carbon steel formulation that gave them strength, resilience, the ability to hold a keen edge, and a visible moire pattern in the steel that give the blades their name.
This interesting phenomenon may be ascribed to superimposition of the graphitic C  peak (20 of 44.608[degrees]) and the cementite
[Fe.sub.3]C peak (2[theta] of 44.575[degrees]) with the Fe peak (2[theta] of 44.662[degrees]).
It is thought that this increase is due to thermal effect accompanied with the softening mechanism by formation of soft microstructural constituent (decomposition of cementite
leads to more ferrite formation) during service time of the tube at these temperatures.