PENGARUH TEMPERATUR DAN MEDIA PENDINGIN PADA PROSES HEAT TREATMENT TERHADAP SIFAT MEKANIS BAJA S45C UNTUK APLIKASI MATA POTONG PENCACAH PLASTIK

Plastic chopper blade or knife is a part that is used as a tool to cut waste plastic
into small parts to be processed to the recycling stage. JIS S45C steel is used as an
alternative material to replace plastic chopper blades. Researchers will vary the
hardening temperature, namely 800°C, 840°C, 880°C with cooling media using salt
water, oil, and sea water. then proceed with the tempering process at a temperature
of 500°C. The mechanical properties in this research are hardness testing and
toughness testing which aims to find the highest value to achieve cutting edge
hardness. From the test results on the hardening process with salt water media
which has the highest hardness at a temperature of 840°C of 50.56 HRC and a
temperature of 880°C of 55.3 HRC. Then after being tempered at a temperature of
500°C, the hardness decreased with a value of 34.01 HRC at a temperature of
840°C with a toughness value of 0.5828 J/mm2 and 36.86 HRC at a temperature of
880°C with a toughness value of 0.3922 J/mm2
it can be concluded that in order to
achieve a reference to the hardness value of the cutting edge of 46.9 HRC in salt
water media with a hardening process it has been achieved it's just that the steel is
brittle, whereas after tempering, the hardness value has not been reached.
Keywords: Hardness, Knife, Toughness, S45C