Analisa Pengaruh Masukan Panas Terhadap Struktur Mikro Dan Sifat Mekanik Temper Bead Welding Pada Material Astm A36

Sitompul, Dany Sanjaya (2019) Analisa Pengaruh Masukan Panas Terhadap Struktur Mikro Dan Sifat Mekanik Temper Bead Welding Pada Material Astm A36. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Dalam proses pembuatan kapal dengan bahan utama baja tidak akan lepas dari proses pengelasan. Akan tetapi, dalam proses pengelasan sering muncul permasalahan cacat las dan deformasi. Post Weld Heat Treatment (PWHT) merupakan salah satu metode perlakuan panas yang dilakukan dalam pengelasan. Tujuan utama dilakukannya PWHT adalah untuk mengurangi residual stress dan meningkatkan ketangguhan hasil pengelasan. Untuk mengoptimasikan sifat pengelasan dalam baja modern di mana PWHT tidak dilakukan atau dipraktekkan maka metode khusus pengelasan digunakan, yaitu Temper Bead Welding (TBW). Untuk mengganti efek dari PWHT, teknik temper bead welding dapat dilakukan sebagai metode alternatif untuk memberikan perlakuan terhadap bead atau atau lapisan las dengan heat input pengelasan pada lapisan atau layer setelahnya. Dalam eksperimen ini, dilakukan perbandingan pengelasan antara Temper Bead Welding dan Post Weld Heat Treatment. Proses pengelasan temper bead dilakukan dengan memvariasikan rasio heat input antar layer sebesar 1.2, 1.3, 1.4, dan pengelasan nontemper bead + Post Weld Heat Treatment. Material yang diigunakan dengan tebal 40 mm. Proses pengelasan yang digunakan adalah Shielded Metal Arc Welding (SMAW). Selanjutnya dilakukan pengujian yang mencakup uji impak, uji kekerasan, dan struktur mikro.
Berdasarkan hasil pengujian dapat diketahui bahwa nilai kekerasan tertinggi terdapat pada rasio heat input 1.4 sebesar 218.06 HV dan nilai kekerasan terendah terdapat pada pengelasan nontemper bead + PWHT sebesar 138.8 HV. Nilai energi absorb daerah weld metal pada pengelasan nontemper bead+PWHT sebesar 133.83 Joule, pada pengelasan temper bead rasio heat input 1.2 sebesar 134.83 Joule, pengelasan temper bead rasio heat input 1.3 sebesar 141.17 Joule, dan pengelasan temper bead rasio heat input 1.4 sebesar 140.17 Joule yang menunjukkan bahwa semakin besar rasio heat input semakin rendah kekuatan impaknya. Secara keseluruhan pengelasan temper bead dengan rasio heat input yang rendah yaitu 1.2 dapat menghasilkan sifat mekanik yang baik mendekati hasil pengelasan yang sesudahnya dilakukan PWHT.
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Steel shipbuilding is inseparable from the welding process; however, welding often results in defects and residual deformation that can reduce the quality of welded joints. Post Weld Heat Treatment (PWHT) is commonly applied to relieve residual stresses and improve the toughness of welds. As an alternative to PWHT, particularly for modern steels where post-weld heat treatment is impractical or unnecessary, the Temper Bead Welding (TBW) technique can be employed. This method utilizes the heat input from subsequent weld passes to temper the previously deposited weld beads, thereby reducing residual stress and improving mechanical properties. This study compares the performance of Temper Bead Welding and conventional welding followed by PWHT on 40 mm-thick steel plates. The TBW process was carried out using heat input ratios between successive layers of 1.2, 1.3, and 1.4, while the comparison specimen consisted of non-temper bead welding followed by PWHT. All specimens were welded using the Shielded Metal Arc Welding (SMAW) process and subsequently evaluated through impact testing, hardness testing, and microstructural analysis. The results indicate that the highest hardness value was obtained with a heat input ratio of 1.4, reaching 218.06 HV, whereas the lowest hardness value of 138.8 HV was observed in the non-temper bead specimen subjected to PWHT. The absorbed impact energy in the weld metal was 133.83 J for the non-temper bead + PWHT specimen, 134.83 J for the TBW specimen with a heat input ratio of 1.2, 141.17 J for a ratio of 1.3, and 140.17 J for a ratio of 1.4. These results indicate that increasing the heat input ratio tends to reduce the impact toughness. Overall, Temper Bead Welding with a heat input ratio of 1.2 produced mechanical properties that were comparable to those achieved through conventional welding followed by PWHT, demonstrating its potential as an effective alternative to post-weld heat treatment.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	ASTM A36, Temper Bead Welding, PWHT, kekerasan, impak, metalografi.
Subjects:	T Technology > TN Mining engineering. Metallurgy > TN690 Metallography. Physical metallurgy T Technology > TN Mining engineering. Metallurgy > TN752.I5 Steel--Heat treatment T Technology > TN Mining engineering. Metallurgy > TN879.6 Welding T Technology > TS Manufactures > TS227 Welding. V Naval Science > VC Naval Maintenance > VC 270-279 Equipment of vessels, supplier,allowances,etc V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM298.5 Shipbuilding industri. Shipyards
Divisions:	Faculty of Marine Technology (MARTECH) > Naval Architecture and Shipbuilding Engineering > 36201-(S1) Undergraduate Thesis
Depositing User:	Sitompul Dany Sanjaya
Date Deposited:	14 Jun 2024 01:16
Last Modified:	23 Jul 2026 03:27
URI:	http://repository.its.ac.id/id/eprint/68347

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