Analisis Pengaruh Posisi Pengelasan Terhadap Nilai Kekuatan Pada Sambungan Plat Baja ASTM A36 Di Lingkungan Laut

Mahendrastama, Yusuf Fahdhia (2023) Analisis Pengaruh Posisi Pengelasan Terhadap Nilai Kekuatan Pada Sambungan Plat Baja ASTM A36 Di Lingkungan Laut. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pengelasan di bawah air (underwater wet welding) adalah proses pengelasan yang dilakukan di dalam lingkungan air atau media cair lainnya. Proses pengelasan ini sering digunakan dalam konstruksi bawah air seperti pembangunan struktur penahan air, pipa bawah air, dan instalasi lepas pantai. Dalam pengelasan bawah air, terdapat beberapa metode pengelasan yang dapat diterapkan, salah satunya adalah metode SMAW. Pada penelitian ini akan membahas perbandingan hasil dari uji tarik, uji bending, serta uji metalografi struktur mikro dan makro menggunakan perbedaan variasi posisi pengelasan dan salinitas 33‰ dan 37‰ serta darat sebagai variabel kontrol. Dari hasil penelitian ditemukan bahwa pada pengelasan bawah air, semakin tinggi salinitas air laut, maka nilai yield strength dan ultimate strength akan semakin besar, serta posisi 1G memiliki keunggulan nilai yield strength dan ultimate strength dibandingkan posisi 2G. Akan tetapi, didapatkan hasil uji bending dari semua spesimen pengelasan bawah air mengalami kegagalan. Sedangkan pada hasil uji makro, spesimen pengelasan bawah air memiliki cacat las porositas yang disebabkan oleh pendinginan antar lapisan weld metal yang drastis. Serta pada hasil uji mikro didapatkan bahwa semakin tinggi salinitas air laut, maka kandungan pearlite akan semakin tinggi dan posisi 1G memiliki kandungan pearlite yang lebih tinggi dibandingkan posisi 2G.
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Underwater welding is a welding process performed in an aquatic or marine environment. This welding technique is commonly used in underwater construction projects such as water retaining structures, underwater pipelines, and offshore installations. In underwater welding, several welding methods can be applied, one of which is the Shielded Metal Arc Welding (SMAW) method. This study aims to compare the results of tensile testing, bending testing, as well as macro and micro metallographic testing using different welding positions and salinity levels of 33‰ and 37‰, with a land-based welding as the control variable. The research findings indicate that in underwater welding, higher salinity levels in seawater result in increased values of yield strength and ultimate strength. Additionally, the 1G welding position demonstrates superior yield strength and ultimate strength compared to the 2G position. Nevertheless, the bending test results of all underwater welding specimens resulted in failure. Furthermore, the macro metallographic examination revealed porosity defects in the underwater welding specimens, which were caused by rapid cooling between weld metal layers. In terms of microstructure, it was observed that higher salinity levels in seawater lead to an increased pearlite content, and the 1G position exhibits a higher pearlite content compared to the 2G position.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	underwater welding, welding positions, salinity
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA492.W4 Welded joints T Technology > TN Mining engineering. Metallurgy > TN879.6 Welding T Technology > TS Manufactures > TS227 Welding.
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User:	Yusuf Fahdhia Mahendrastama
Date Deposited:	20 Jul 2023 08:52
Last Modified:	20 Jul 2023 08:52
URI:	http://repository.its.ac.id/id/eprint/98756

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