ANALYSIS OF THE EFFECT
OF CRYOGENIC TREATMENT
IN HIGH CARBON STEELS
Cu Amiel Benedict, Publico Jerome,
Menor Jesli
Introduction
The word, Cryogenics is taken from two Greek
words kryos which means frost or freezing,
and genic meaning to produce or generated.
Technologically, it means the study and use of
materials at very low temperatures.
The cryogenic treatment is a method to increase
hardness and wear resistance and improve surface
finish for cutting tools, dies and critical machined
parts.
Statement of the problem
The main purpose of the study is to determine the
effects of cryogenic treatments on high carbon steel.
Specifically, the study sought to answer the following:
1.) Analyze the effects of treatments in the following
after it is been done:
a. Hardness Test
b. Ductility Test
c. Molecular Structure
Objective
To study the properties of high carbon
steels during Cryogenics treatment
To determine the structure and behavior of
high carbon steel under the process of
Cryogenic treatment.
To verify the gradual improvement of a
particular high carbon steel materials under
the Cryogenic treatment
To establish the different applications of
cryogenic treatment.
Scope and limitations
In some applications in which explicit
amounts of retained austenite are
considered beneficial, cold treating
might be detrimental. Moreover, multiple
tempering rather than alternate freezetemper cycling, generally is more
practical for transforming retained
austenite in high-speed and highcarbon/high-chromium steels
Related Literature
Cryogenic hardening it is a heat treating
process, it is combination of heating and
cooling that is applied into metal and alloys.
Carbon steel is a compound comprising of
iron and carbon.
Low Carbon steel
Medium Carbon steel
High Carbon steel
Methodology Flow chart
Preparation of materials
Collection of Steels
Administration of the treatment
Gather the data
Disposal
Analyze the data
Process
Austenetize
Quenching
Cryoprocess
Tempering
Austenitize
Austenitization means to heat the iron, iron-based
metal, or steel to a temperature at which it changes
crystal structure from ferrite to austenite.
Quenching
After Austenitising temperature,the steel is cooled
to ambient temperature rapidly in a suitable
quenching media like water,oil,air.
Once the austenite is cooled below its critical
temperature,it becomes unstable and it starts to
transform in to martensite.
After CHT there would always be some retained
austenite in the steel.Which is up to 20-30%.
Cryotreatment
Cryogenic Treatment (CT) of tool materials
consists of three stages
Cooling of tool material fromroom temperature,
at an extremely slow rate ranging from0.5 to 1
C/min,,
Shallow Cryogenic Treatment (SCT) for the
period of -84 C,
Deep Cryo-genic Treatment (DCT) for the period
of -196 C,
Tempering
Tempering is the process of reheating the steel at
predetermined temperatures which is lower than the
transformational temperature.
Martensite precipitates fine carbides, which are
named as transition carbides. Nucleation of these
carbides relieves micro-stresses inthe brittle
primary martensite and prevents micro cracking on
surface of the steel
Almost all of the austenite retained in the steel after
heat-treating is transformed into a harder form,
martensite, by means of the cryogenic process. An
addition result is the formation of fine carbide
particles, called binders, to complement the larger
carbide particles present before cryogenic
treatment. Untransformed austenite is very brittle
and can cause loss of strength or hardness, or
cracking.
Instruments
Applications
Gun barrels: increases the wear life of the barrel
and makes cleaning easier and faster
Grinding: allows a better cut, a better finish, and
less tensile residual induced into the workpiece
Machining: lathes, drill bits, cutting and milling
tools
Dental and Surgical Instruments
Engine Parts
Sources
www.sciencedirect.com/
Material science and metallurgy
Kestoor praveen
http://www.bmsce.ac.in/sites/default/files
/Dubai%20paper_0.pdf
research.ijcaonline.org/iccia/number9/icc
ia1068.pdf
