The Effect of Salt Content in Cooling Media in the Quenching-Tempering Process on the Torsional and Impact Strength of S45C Steel
ABSTRAK
Gangguan pada mesin perontok padi seringkali disebabkan oleh kapasitas pengumpanan yang berlebihan. Hal tersebut mengakibatkan poros silinder perontok mengalami beban puntir akibat pengaruh motor penggerak dan beban kejut akibat pengaruh transmisi pulley. Berdasarkan permasalahan tersebut maka dilakukan penelitian dengan tujuan mengetahui pengaruh metode perlakuan panas quenching-tempering dengan variasi kadar garam pada media pendingin terhadap kekuatan puntir dan impak dari material poros mesin perontok padi, yaitu material baja S45C.
Penelitian ini merupakan jenis penelitian eksperimen. Metode perlakuan panas yang digunakan yaitu quenching-tempering. Material baja S45C dimasukkan ke dalam tungku (furnace) dan dipanaskan dengan temperatur 850°C, holding time selama 15 menit, kemudian dilakukan proses quenching dengan media pendingin air garam 0%, 10%, 20%. Selanjutnya dilakukan proses tempering dengan temperatur 300°C, holding time selama 15 menit dan didinginkan menggunakan suhu ruang atau udara. Setelah itu dilakukan pengujian kekuatan puntir dan kekuatan impak. Teknik analisis data yang digunakan yaitu teknik analisis regresi.
Adapun hasil dari penelitian menunjukkan variasi air garam 20% memiliki nilai tegangan puntir tertinggi yaitu sebesar 20,04 N/mm2, dan terendah pada variasi air garam 0% sebesar 18,22 N/mm2. Sedangkan nilai kekuatan impak tertinggi pada variasi air garam 0% sebesar 0,4137 Joule/mm2, dan terendah pada variasi air garam 20% yaitu sebesar 0,2447 Joule/mm2. Semakin tinggi kadar garam pada media pendingin, maka semakin tinggi juga kekuatan puntirnya dan material baja S45C akan memperoleh sifat tahan beban puntiran yang lebih baik. Namun, di sisi lain menurunkan kekuatan impak serta ketangguhan dari material baja S45C.
Kata Kunci: Quenching, Tempering, Kekuatan Puntir, Kekuatan Impak, Baja S45C, Kadar Garam
ABSTRACT
Disturbances in rice threshing machines are often caused by excessive feeding capacity. This causes the threshing cylinder shaft to experience torsional loads due to the influence of the driving motor and shock loads due to the influence of the pulley transmission. Based on these problems, a study was conducted with the aim of determining the effect of the quenching-tempering heat treatment method with variations in salt content in the cooling medium on the torsional and impact strength of the rice threshing machine shaft material, namely S45C steel material.
This research is an experimental research. The heat treatment method used is quenching-tempering. S45C steel material is inserted into the furnace and heated to a temperature of 850°C, holding time for 15 minutes, then the quenching process is carried out with a coolant of 0%, 10%, 20% salt water. Furthermore, the tempering process is carried out at a temperature of 300°C, holding time for 15 minutes and cooled using room temperature or air. After that, torsional strength and impact strength tests are carried out. The data analysis technique used is the regression analysis technique.
The results of the study showed that the variation of 20% salt water had the highest torsional stress value of 20.04 N/mm2, and the lowest in the variation of 0% salt water of 18.22 N/mm2. While the highest impact strength value in the variation of 0% salt water was 0.4137 Joule/mm2, and the lowest in the variation of 20% salt water was 0.2447 Joule/mm2. The higher the salt content in the cooling medium, the higher the torsional strength and the S45C steel material will obtain better torsional load resistance properties. However, on the other hand, it reduces the impact strength and toughness of the S45C steel material.
Keywords: Quenching, Tempering, Torsional Strength, Impact Strength, S45C Steel, Salt Content