In this work, Ck85 carbon steel was subjected to cyclic heat
treatment.
Process that consisted of cyclic short-duration (3.4 minutes)
holding at 800 C (above Ac3 temperature) followed by forced air
cooling. After 8 cycles (about a total 1 hour du
ration of heating and cooling cyclic), the microstructure mostly contained fine ferrite
grains and spheroidzed cementite. This microstructure possessed
an excellent combination of strength and ductility. The disintegration of lamellar pearlite through dissolution of cementite
at boundaries lamellar during short-duration holding above Ac3
temperature, and the generation of lamellar defects during nonequilibrium forced air cooling were the main reasons of
accelerated spheroidization. The strength initially increased mainly
due to the presence of finer microconstituents (ferrite and pearlite)
and then marginally decreased with the elimination of lamellar
pearlite and appearance of spheroid cementite in the microstructure.
When we visited the United Arab Company for Spinning and Weaving In the capital, Damascus, we found
a lot of problems in the units of feeding steam, and the most prominent of these problems occur corrosion
in the pipe of steam boilers, And the coll
apse in the heat exchanger on the thread dyeing machine (the
collapse of the body and pipes), so we took a group of samples in the places that suffer problems in order
to determine the mechanical and chemical properties, we found through analysis that the boiler tubes
were made of carbon steel, while the tubes and the body of heat exchanger was made of stainless steel, has
been shown through research that pipe boilers of carbon steel suffers of problems as a result overheating,
hydrogen damage and an attack Oxide, And the body of heat exchanger was suffering from an corrosion
Cracking result of the high proportion of chromium in it (chromium ratio up to 17%), has been
developing a set of solutions represented to be the metal surfaces clean and homogeneous, and must be
feed water free of salts, suspended solids, and gases
This paper provides a mechanism to study aluminum diffusion microstructure, phase
structure and different properties of the aluminized layer in carbon steel.
The results of aluminized treatment in saturated medium lead to the formation of diffusion
layer coating that contains iron aluminide and a- solid solution of aluminum in the unit cell of
iron.
The effect of aluminizing process parameters on the aluminizing layer, especially the
effect of temperature and time, has been shown to increase the depth of the aluminized layer
when temperature and time increase, but the effect of temperature is greater than time.
The effects of induction hardening on mechanical properties of two kinds of carbon
steel (0.59%C , 0.35%C) that are widely used in local industry, were discussed by exposed
specimens that were induction hardened with different values of power and i
nductor's
speed to hardness, tensile, and impact tests.
The results of tests showed that the mechanical properties become greater with slight
decrease in impact energy of carbon steel when induction hardening is used, and showed
the possibility to do control on product's properties by make control on treatment
parameters .
