Pengaruh Variasi Jarak Penembakan Pada Proses Shot Peening Terhadap Kekerasan Dan Laju Korosi Pipa ASTM A 106 Pada Sambungan Las SMAW

Pria Nugroho, Ferdiansyah (2021) Pengaruh Variasi Jarak Penembakan Pada Proses Shot Peening Terhadap Kekerasan Dan Laju Korosi Pipa ASTM A 106 Pada Sambungan Las SMAW. Sarjana thesis, Universitas Brawijaya.

Abstract

Permintaan energi akan meningkat dari tahun ke tahun karena populasi dunia terus bertambah. International Energy Agency (IEA) sudah memperkirakan bahwa dalam 20 tahun ke depan, setidaknya kebutuhan energi dunia akan datang dari minyak bumi dan akan menjadi sumber energi yang dominan. Untuk mengalirkan minyak tersebut dibutuhkan sistem pemipaan untuk mengalirkan minyak ke kilang dan bisa dikonsumsi. Sistem pemipaan pada umumnya dipasang dan diperbaiki dengan proses pengelasan busur listrik seperti MIG / MAG, SMAW, TIG. Namun demikian, masih terdapat kekurangan pada pengelasan yaitu munculnya tegangan sisa tarik dimana dapat mengakibatkan kegagalan premature dan menyebabkan terjadinya stress corrosion cracking. Dimana jenis kegagalan seperti ini sering terjadi pada sambungan las pipa minyak. Oleh karena itu diberikan perlakuan shot peening untuk mengurangi tegangan sisa tarik. Proses shot peening yaitu proses pengerjaan dingin pada permukaan dimana dengan menembakkan bola bola kecil ke permukaan logam dengan menggunakan semburan udara yang terkompresi. Pada penelitian kali ini menggunakan variasi jarak penembakan yaitu 6 cm, 8 cm, 10 cm, 12 cm, dan 14 cm, dengan bola baja berdiameter 3 mm, lama waktu penembakan 10 menit dan tekanan 8 bar untuk mencari pengaruhnya terhadap nilai kekerasan dan laju korosi. Nilai kekerasan diambil dari permukaan dengan kedalaman 0,3 mm, 0,5 mm, an 0,7 mm menggunakan microvickers hardness dan uji korosi menggunakan alat potentiostat / galvanostat (PalmSens). Pada penelitian ini foto makro digunakan sebagai data pendukung. Hasil dari penelitian ini menunjukkan bahwa semakin rendah jarak tembakan pada proses shot peening dapat meningkatkan kekerasan dan menurunkan laju korosi pada sambungan las pipa ASTM a 106 grade B.

English Abstract

Ferdiansyah Pria Nugroho, Department of Mechanical Engineering, Faculty of Engineering Universitas Brawijaya, Juny 2021, The effect of Shot Distance Variations on Shot Peening Process on Hardness and Corrosion Rate ASTM A 106 Pipe on SMAW Welding Joints, Academic Advisor’s: Teguh Dwi Widodo, ST., M.Eng. Ph.D., dan Rudianto Raharjo ST., MT. Energy demand will increase from year to year as the world population continues to grow. The International Energy Agency (IEA) has predicted that in the next 20 years, at least the world's energy needs will come from petroleum and will become the dominant energy source. To drain the oil, a piping system is needed to drain the oil to the refinery and it can be consumed by the public. Piping systems are generally installed and repaired by electric arc welding processes such as MIG/MAG, SMAW, TIG. However, there are still weaknesses in welding, namely the emergence of residual tensile stresses that can lead to premature failure and cause stress corrosion cracking. Where this type of failure often occurs in oil pipe welding connections coupled with the presence of a corrosive fluid, namely crude oil. The residual tensile stress here arises because of the heat cycle during the welding process. Therefore, shot peening was given to reduce the residual tensile stress. The shot peening process is a cold working process on a surface where by firing small balls onto a metal surface using a jet of compressed air. In this research using the shot peening process with variations in shooting distances, namely 6 cm, 8 cm, 10 cm, 12 cm, and 14 cm, with a steel ball with a diameter of 3 mm, a shooting time of 10 minutes and a pressure of 8 bar to find a suitable shooting distance optimally in the shot peening process on the value of hardness and corrosion rate on SMAW weld joints of ASTM A 106 grade B pipes. Hardness values were taken from the surface with a depth of 0.3 mm, 0.5 mm, and 0.7 mm using microvickers EW-412AAT Corrosion test using a potentiostat / galvanostat (PalmSens) with crude oil as the corrosion solution. In this research, macro photos and SEM (Scanning Electron Microscope) photos were used as supporting data. The results of this research show that with a lower shooting distance in the shot peening process, the corrosion rate value is lower and the hardness value is increasing, while with a higher firing distance, a high corrosion rate value and a low hardness value are obtained. The results of SEM and macro photos in this research have also supported the results of research on corrosion rate testing. The shooting distance in the optimal shot peening process in this research is a shooting distance of 6 cm, the corrosion rate value is 0.090 mm/year and the highest hardness value is 341.8 HV. Keywords: Shot Peening, Hardness, Corrosion Rate, ASTM A106 grade B

Other obstract

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Item Type: Thesis (Sarjana)
Identification Number: 521.8
Uncontrolled Keywords: Kata Kunci: Shot Peening, Kekerasan, Laju Korosi, ASTM A106 grade B--Shot Peening, Hardness, Corrosion Rate, ASTM A106 grade B
Subjects: 600 Technology (Applied sciences) > 621 Applied physics > 621.8 Machine engineering
Divisions: Fakultas Ekonomi dan Bisnis > Akuntansi
Depositing User: Unnamed user with username gaby
Date Deposited: 20 Oct 2021 07:16
Last Modified: 23 Feb 2022 08:02
URI: http://repository.ub.ac.id/id/eprint/184343
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