Analisis pengaruh variasi arus dan tegangan pengelasan metode FCAW terhadap struktur mikro dan sifat mekanik sambungan baja S355JR

Habiburrahman, Izzuddin (2022) Analisis pengaruh variasi arus dan tegangan pengelasan metode FCAW terhadap struktur mikro dan sifat mekanik sambungan baja S355JR. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Industri Kereta Api Indonesia merupakan salah satu industri strategis. Proses pengelasan merupakan tahap manufaktur kereta. Metode pengelasan FCAW tepat digunakan dalam perakitan gerbong kereta api. Baja S355JR merupakan baja struktural yang umum digunakan karena sifat mampu las yang baik. Variasi arus dan tegangan menjadi faktor penting yang diperhatikan dalam parameter pengelasan. Tujuan dari penelitian ini adalah menganalisis pengaruh variasi arus dan tegangan pengelasan terhadap struktur mikro dan sifat mekanik baja S355JR. Adapun variasi arus dan tegangan yang digunakan pada penelitian ini adalah Arus 170 A, 190 A, 200 A, tegangan 26,5 V dan 27,5 V. Skema penelitian yang dilakukan dengan melakukan pengelasan pada sepasang plat baja dimensi 250 mm x 125 mm x 14 mm posisi 1G. Kemudian dilakukan pengujian sifat mekanik yang meliputi uji tarik dan uji kekerasan. Sedangkan struktur mikro dilakukan uji metalografi. Hasil pengujian tarik menunjukkan adanya pengaruh arus dan tegangan pada nilai ultimate tensile strength, yield strength, dan elongation. Variasi arus 200 A tegangan 26,5 V memiliki nilai tertinggi yaitu, tensile strength 526,80 MPa, yield strength 382,25 MPa, dan elongation 28,70%. Pada pengujian kekerasan didapatkan peningkatan distribusi kekerasan pada daerah HAZ dan weld metal dibandingkan base metal. Terjadi transformasi ukuran butir struktur mikro daerah HAZ dan weld metal. Struktur mikro HAZ dan weld metal cenderung lebih halus dari base metal baja S355JR. Semakin rendah masukan panas pengelasan, maka struktur mikro semakin halus. Ketiga daerah tersebut tidak terjadi perubahan fasa pada struktur mikro. Dari sifat mekanik didapatkan hasil yang paling optimal didapatkan pada variasi arus 200 A dan tegangan 26,5 V. Variasi tersebut memiliki nilai tensile strength 526,80 MPa, yield strength 382,25 MPa, dan elongation 28,70%. Untuk nilai kekerasan pada HAZ 251,67 HV dan pada weld metal 242,33 HV.
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The Indonesian Railway Industry is one of the industrial strategies. The welding process is a stage of manufacturing trains. The FCAW welding method is appropriate for the assembly of railroad cars. S355JR steel is a commonly used structural steel due to its good weldability. Current and voltage variations are important factors to consider in parameter welding. The purpose of this study was to analyze the effect of current and welding variations on the microstructure and mechanical properties of S355JR steel. The current and voltage variations used in this study are currents 170 A, 190 A, 200 A, voltage 26.5 V and 27.5 V. The scheme of the study was carried out by welding on a pair of steel plates with dimensions of 250 mm x 125 mm x 14mm position 1G. Then the mechanical properties were tested which included tensile test and hardness test. Meanwhile, the microstructure was tested by metallography. The test results show the influence of current and stress on the ultimate tensile strength, yield strength, and elongation. The current variation of 200 A with a voltage of 26.5 V has the highest value, namely, tensile strength of 526.80 MPa, yield strength of 382.25 MPa, and elongation of 28.70%. The hardness test showed an increase in the distribution of hardness in the HAZ area and the weld metal compared to the base metal. There was a grain size transformation of the microstructure of the HAZ region and the weld metal. The microstructure of HAZ and weld metal more fine than the base metal of S355JR steel. The lower the welding heat input, the finer the microstructure. The three regions did not have a phase change in the microstructure. From the mechanical properties, the most optimal results were obtained at a current variation of 200 A and a voltage of 26.5 V. These variations had a tensile strength value of 526.80 MPa, yield strength 382.25 MPa, and elongation 28.70%. For the value of hardness on HAZ 251.67 HV and on weld metal 242.33 HV.

Item Type:	Thesis (Other)
Additional Information:	RSMt 671.52 Hab a-1 2022
Uncontrolled Keywords:	Arus, Tegangan, Pengelasan, FCAW, Current, Voltage, Welding
Subjects:	T Technology > TN Mining engineering. Metallurgy > TN879.6 Welding
Divisions:	Faculty of Industrial Technology > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	Mr. Marsudiyana -
Date Deposited:	10 Feb 2025 03:10
Last Modified:	10 Feb 2025 03:10
URI:	http://repository.its.ac.id/id/eprint/118581

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