EFFECT OF DEEP CRYOGENIC TREATMENT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AISI O1 TOOL STEEL WITH TEMPERING TEMPERATURE VARIATION
Tool Steel AISI O1 is one of the important metals in human life. This steel is a highcarbon steel that is combined with elements such as chromium, tungsten, manganese, and vanadium. AISI O1 is generally given conventional heat treatment, but there is still a lot of retained austenite. AISI O1 is...
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| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/86379 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Tool Steel AISI O1 is one of the important metals in human life. This steel is a highcarbon
steel that is combined with elements such as chromium, tungsten,
manganese, and vanadium. AISI O1 is generally given conventional heat treatment,
but there is still a lot of retained austenite. AISI O1 is commonly used as Dies
Stamping in the manufacturing industry. This steel is notoriously hard but brittle so
that Dies Stamping often breaks after some time of use. There are several methods
to make AISI O1 hard but still tenacious. One alternative method is Deep Cryogenic
Treatment (DCT). DCT is a method of soaking steel at very low temperatures to
convert retained austenite into fully martensitic. This study aims to analyze the
influence of tempering temperature variations on the conventional heat treatment
process and DCT.
Experiments of conventional heat treatment methods and DCT on AISI O1 steel
were conducted to analyze their effects on microstructure and mechanical
properties. The experiment was carried out with an impact test specimen with a
variation in tempering temperature. The steel will be austenized at a temperature of
950 oC for 30 minutes so that the phase becomes fully austenite. Then the steel is
quenched using oil and continued tempering at temperatures of 200 oC, 250 oC,
300 oC, 400 oC, and 500 oC for 2 hours. Steel that has been subjected to
conventional heat treatment will be DCT. Then characterizations such as impact
tests, Vickers hardness tests, metallographies using optical microscopes, XRD
analysis, and SEM-EDS analysis were carried out. From the characterization
analysis data, the effect of conventional heat treatment and DCT on microstructure
and mechanical properties was determined.
The results of the experiment showed that retained austenite turned into martensitic
when DCT was performed, which increased its hardness. The hardness value of
DCT is higher than that of conventional heat treatment. The trend of hardness
decreases linearly with the increase in tempering temperature. The maximum
hardness is obtained from the variation of DCT at a tempering temperature of
250 °C with a hardness value of 702 HV. The toughness value when DCT is
performed is also higher compared to conventional heat treatment. The trend of
toughness increases linearly with the increase in tempering temperature. The
maximum toughness is obtained from the variation of DCT at a tempering
temperature of 500 °C with a toughness value of 9.4 Joules. The faults that occur in
impact specimens are mixed faults, namely transgranular and intergranular |
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