Selection of Material and Heat Treatment Cycle for Wear Reduction in Oil Palm (Elaeis Guineensis) Harvesting Knives
Izbor materijala i ciklus kaljenja radi smanjenja habanja noževa za berbu
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Author
Singh, Dushyant
Saha, K.P.
Naik, Ravindra
Bhushanbabu, V.
Prasad, M.V.
Singh, Vidhan
Keywords
wear ratesteel,
heat-treatment
mechanical properties
oil palm harvesting
stepen habanja
čelik
kaljenje
mehaničke osobine
berba
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Show full item recordAbstract
Harvesting of oil palm is a tedious and labor intensive work. Nonavailability
of proper tool increases the severity of the problem. Knives used for
harvesting the oil palm are either imported or made by local artisans using locally
available scrap material. In the present study, oil palm harvesting knives imported from
Malaysia and locally made by manufactures in Kerala, India were tested for chemical
composition and hardness. On the basis of the results, medium carbon steel was selected
for fabrication of oil palm harvesting knives. To obtain the various combinations of
microstructure, mechanical properties and wear resistance; these knives were subjected
to quenching and tempering treatment with varying tempering temperature (from 250 to
550°C at an interval of 50°C). Abrasive wear resistance of this steel before and after
heat-treatment was studied in laboratory using dry sand abrasion test rig as per ASTM G
65 standard at different rotational speed of rubber wheel ranging from 50 to 200 min-1 at
an interval of 50 min-1. The study revealed that both the factors i.e. tempering
temperature and rotational speed of rubber wheel exerted significant influence on
abrasive wear resistance. At 250°C tempering temperature, the hardness and abrasive
wear resistance is observed to be maximum under the laboratory evaluation. Similar
wear resistance behavior was also observed under field condition when the knives were
used to cut frond and bunch of oil palm by human laborers. Berba palmi je naporan i intenzivan postupak. Problem je izraženiji
zbog nedostatka odgovarajućih alata. Noževi koji se koriste se uvoze ili ih izrađuju
lokalne zanatlije od otpadnog gvožđa. Ovde su ispitivani noževi uvezeni iz Malezije i
noževi lokalne proizvodnje, a određivan im je hemijski sastav i tvrdoća. Na osnovu
rezultata izabran je srednje ugljenični čelik za izradu noževa. Za dobijanje različitih
kombinacija mikrostrukture, mehaničkih osobina i otpora habanju ovi noževi su grejani i
naglo hlađeni na različitim temperaturama (od 250 do 550°C u intervalu od 50°C). Otpor
ovog čelika na abrazivno habanje pre i posle kaljenja je ispitivano u laboratoriji
upotrebom abrazivnog testa sa suvim peskom prema standardu ASTM G 65, sa različitim
brzinama rotacije gumenog točka, od 50 do 200 min-1 u intervalu od 50 min-1.
Ispitivanjem je utvrđeno da su oba faktora, temperature kaljenja i brzina rotacije
gumenog točka, imala značajan uticaj na otpor abrazivnom habanju. Na temperature od
250°C dobijeni su maksimalna tvrdoća i otpor habanju u laboratorijskim uslovima.
Sličan otpor habanju uočen je i u poljskim uslovima, kada su noževi korišćeni za ručno
sečenje lišća i grana.