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Suryanto Edi - One of the best experts on this subject based on the ideXlab platform.

  • Pengaruh Heat Input Terhadap Sifat Mekanik Sambungan Dissimilar Metal Antara Austenitic Stainless Steel SS 304h Dan Low Alloy Steel T22 Dengan Proses GTAW
    2018
    Co-Authors: Suryanto Edi
    Abstract:

    Pengelasan logam yang berbeda (DMW) mengacu pada gabungan dua logam atau paduan yang berbeda seperti baja paduan rendah (low alloy steel), baja tahan karat (stainless steel) dan paduan nickel-base. Kelemahan pengelasan Dissimilar Metal yang mendasar adalah perbedaan komposisi kimia material, sifat mekanik dan sifat Metalurgi yang dapat menyebabkan kegagalan pada sambungan ketika di las. Penyebab utama kegagalan pada sambungan akibat adanya perubahan komposisi kimia sepanjang garis fusi. Perbedaan koefisien termal ekspansi masing-masing material juga turut menyebabkan degradasi sifat mekanik di zona fusi yang dapat memicu stress dan rentan terhadap retakan. Untuk mencegahnya dapat dilakukan dengan cara memprediksi komposisi kimia pada weld Metal, mengontrol masukan panas atau heat input pengelasan, pelapisan (buttering) pada logam induk, dan juga melakukan post weld heat treatment (PWHT) untuk memperkecil tegangan sisa pada pengelasan. Material yang digunakan pada penelitian ini tube SS 304H dengan low alloy steel T22 dengan variasi heat input 3,500 kJ/mm, 3,182 kJ/mm dan 2,714 kJ/mm. Proses pengelasan dilakukan menggunakan jenis pengelasan GTAW. Selanjutnya hasil pengelasan dilakukan pengujian dye penetrant, pengujian tarik, pengujian bending. Pada penelitian ini didapatkan nilai kekuatan tarik rata-rata pada spesimen dengan heat input 3,500 kJ/mm sebesar 508,96 MPa, pada spesimen heat input (3,182 kJ/mm) sebesar 510,83 MPa, pada spesimen heat input (2,714 kJ/mm) sebesar 513,12 MPa. Letak patahan semua spesimen berada di sisi low alloy steel T22 akibat pengaruh proses pengelasan multilayer, yang menunjukkan kekuatan sambungan weld Metal lebih kuat dari pada base Metal. Untuk hasil pengujian root bending dan face bending didapatkan hasil tidak adanya retakan pada semua spesimen lasan. Hal ini menunjukan ductility semua spesimen hasil lasan yang baik dan dinyatakan lolos kualifikasai standar ASME section IX. ========== Dissimilar Metal Welding (DMW) is a combination of two different Metals or alloys such as low alloy steel, stainless steel and nickel-base alloys. The disadvantages of basic Metal Dissimilar Welding are differences in chemical composition of materials, mechanical properties and Metallurgical properties that can lead to failure of the joints when welded. The main cause of failure of the connection due to changes in chemical composition along the fusion line. Differences in the thermal coefficients of each material expansion also contribute to the degradation of mechanical properties in the fusion zon e which can be stressful and susceptible to cracks. To prevent it can be done by predicting the chemical composition of the weld Metal, controlling the heat input or heat input Welding, buttering on the base Metal, and also post-weld heat treatment (PWHT) to minimize residual stress on Welding. The material used in this research is SS 304H tube with low alloy steel T22 with variation of heat input 3,500 kJ / mm, 3,182 kJ / mm and 2,714 kJ / mm. The Welding process is carried out using GTAW. Furthermore, the Welding results are testing by dye penetrant test, tensile test, and bending test In this research we get the average tensile strength value in specimen with heat input 3,500 kJ / mm equal to 508,96 MPa, on heat input specimen (3,182 kJ / mm) equal to 510 ,83 MPa, on heat input specimen (2,714 kJ / mm ) of 513.12 MPa. The fracture location of all specimens is on the low alloy steel T22 side due to the influence of the multilayer Welding process, which indicates the strength of the weld Metal joints is stronger than the base Metal. For the result of root bending and face bending test, the result of the absence of cracks in all weld specimens. This shows the ductility of all specimens of a good welded result and is declared qualified by ASME section IX standard

S Narayana - One of the best experts on this subject based on the ideXlab platform.

  • effect of filler materials on the performance of gas tungsten arc welded aisi 304 and monel 400
    Materials & Design, 2012
    Co-Authors: Devendranath K Ramkuma, N Arivazhaga, S Narayana
    Abstract:

    Abstract Dissimilar Metal Welding involving AISI 304 and Monel 400 finds widespread use in marine and offshore environments for the fabrication of heat exchangers, evaporators, piping and vessels in petrochemical and power generation industries. However studies on the performance of such weldments are scantly found in the literature even though the individual Metals have higher corrosion resistance and strength. This paper reports the work carried out on Welding of AISI 304 and Monel 400 using Gas Tungsten Arc Welding (GTAW) technique to examine the weldability, mechanical and Metallurgical properties. Investigations have been carried out on the hot corrosion behavior of these joints subjected to cyclic air oxidation and K 2 SO 4  + NaCl (60%) molten salt environment at 600 °C. A comparative analysis was carried out on these weldments for two different filler Metals such as E309L and ENiCu-7. The oxide scales formed on the various zones of the weldment have been characterized systematically using surface analytical techniques. Weld zone was found to be more susceptible to degradation than base Metals used. The effect of filler materials on the hot corrosion is discussed. The studies reported in this paper would be beneficial for fabricators embracing this type of Dissimilar weldments in the petrochemical and power generation industries.

Nugroho,, Sri., Dr. S M - One of the best experts on this subject based on the ideXlab platform.

  • PENGARUH PWHT PADA KUALITAS SPESIMEN PREHEAT PENGELASAN Dissimilar Metal ANTARA BAJA KARBON (A-106) DAN BAJA TAHAN KARAT (A312 TP-304H) DENGAN FILLER Metal INCONEL 82
    2012
    Co-Authors: Sudiarso Wiko, Nugroho,, Sri., Dr. S M
    Abstract:

    Terdapat sebuah alat yang bernama Primary Reformer di PT. Pupuk Kaltim adalah suatu alat yang berbentuk tube yang berfungsi untuk memecahkan gas hydrocarbon menjadi hidrogen. Alat ini dioperasikan pada suhu 600-800oC dan tekanan 30-40 bar. Primary reformer dibuat dari material yang berbeda, material baja karbon (flange) dan material baja tahan karat (top tube). Kedua material tersebut disambung dengan menggunakan las GTAW (Gas Tungsten Arc Welding) dengan filler Metal inconel 82. Namun ditemukan kobocoran (disbonding) antara sambungan pada material baja karbon dan weld Metal. Tugas Akhir ini meneliti pengaruh PWHT (Post Weld Heat Treatment) terhadap kualitas spesimen preheat hasil pengelasan DMW (Dissimilar Metal Welding). Hasil yang diharapkan dari penelitian ini dapat mengungkap lebih jelas penyebab kebocoran pada pipa Primary Reformer di atas. Beberapa pengujian yang dilakukan dalam penelitian ini antara lain : PWHT (tungku heat treatment), struktur mikro (mikroskop optik), dan nilai kekerasan (mikro vikers). Pengujian struktur mikro didapatkan hasil pelebaran ukuran dark band efek dari variasi temperatur PWHT pada batas fusi sambungan baja karbon dan weld Metal, serta terjadi pengkasaran butir pada daerah HAZ baja karbon yang berstruktur full ferit. Nilai kekerasan pada daerah dark band ini lebih tinggi dibanding daerah lainya, dan menurunnya nilai kekerasan pada daerah HAZ baja karbon. Turunya nilai kekerasan pada HAZ baja karbon dapat menimbulkan kegagalan jika komponen ini semakin lama dipakai pada aplikasi tersebut. Kata Kunci: Primary Reformer, disbonding, PWHT, dark band, pengkasaran butir

Youngjin Kim - One of the best experts on this subject based on the ideXlab platform.

  • A RESIDUAL STRESS ANALYSIS OF A CORNER CRACK IN PRESSURIZER VENT NOZZLE PENETRATION WELD
    2020
    Co-Authors: Sang-min Lee, Jeongsoon Park, Young Hwan Choi, Haedong Chung, Dooho Cho, Yoonsuk Chang, Youngjin Kim
    Abstract:

    ABSTRACT There are some ferritic low alloy steel components including Dissimilar Metal Welding parts in a nuclear power plant. Residual stress induced by Welding process is one of the factors that may lead a sound component to have a defect

  • a residual stress analysis of a corner crack in pressurizer vent nozzle penetration weld
    ASME 2009 Pressure Vessels and Piping Conference, 2009
    Co-Authors: Sang-min Lee, Jeongsoon Park, Young Hwan Choi, Haedong Chung, Dooho Cho, Yoonsuk Chang, Youngjin Kim
    Abstract:

    There are some ferritic low alloy steel components including Dissimilar Metal Welding parts in a nuclear power plant. Residual stress induced by Welding process is one of the factors that may lead a sound component to have a defect. Therefore it is necessary that the distribution of residual stress is obtained to predict the behavior of a Dissimilar Metal Welding part. In this paper, the distribution of residual stress obtained by finite element analysis is investigated to assess the stress intensity factor of a corner crack in pressurizer vent nozzle penetration weld. Then the stress intensity factor and plastic zone correction of a corner crack are calculated under internal pressure, thermal stress and residual stress in accordance with Electric Power Research Institute equation [1]. The resulting stress intensity factor and plastic-zone correction were compared with those obtained from Structural Integrity Associates.Copyright © 2009 by ASME

Yorgie Yorgie - One of the best experts on this subject based on the ideXlab platform.

  • Studi Eksperimen Pengaruh Perbedaan Filler Metal Er309 Dan ERNiCr-3 Terhadap Komposisi Kimia Sambungan Las Dissimilar Metal Antara Austenitic Stainless Steel SS347HTB Dan Low Alloy Steel T91 Dengan Proses GTAW
    2019
    Co-Authors: Yorgie Yorgie
    Abstract:

    Dissimilar Metal Welding (DMW) merupakan salah satu metode untuk menyambungkan logam yang berbeda contohnya seperti penyambungan stainless steel (SS) dengan baja paduan karbon rendah. Sambungan kedua jenis logam tersebut umumnya digunakan pada pembangkit listrik khususnya pada bagian tube boiler. Hal ini dikarenakan tube boiler bekerja pada suhu dan tekanan berbeda sehingga akan mempengaruhi penggunaan material yang digunakan. Umumnya pada bagian suhu tinggi terbuat dari baja tahan karat austenite yang memiliki sifat tahan karat yang sangat baik pada suhu dan tekanan tinggi, dan pada bagian dengan suhu lebih rendah digunakan baja paduan dikarenakan nilai keekonomisan dari material tersebut. Namun pada DMW terdapat kekurangan dimana akibat perbedaan komposisi kimia antara material yang terjadi pada sepanjang garis fusi mengakibatkan sifat mekanik dan struktur mikro berbeda sehingga sambungan akan rentan terhadap kegagalan. Salah satu langkah dalam mengurangi permasalah yang terdapat pada DMW adalah dengan memprediksi kandungan komposisi kimia pada weld Metal dimana komposisi kimia dapat diatur dengan cara pemilihan kawat las yang benar sesuai dengan standar yang digunakan Dalam penelitian ini dilakukan pengelasan Dissimilar Metal antara SS347HTB dan low alloy carbon steel (T91) dengan variasi filler Metal ER309 dan ERNiCr-3, dimana voltase dan arus pengelasan sama. Variasi pengelasan ini menggunakan metode gas tungsten arc Welding (GTAW). Setelah dilakukan proses pengelasan dilakukan pengujian merusak ,pengujian Metalurgi dan pengujian SEM-EDS. Pengujian yang dilakukan dalam penelitian ini adalah pengujian kekerasan dengan microvickers, pengujian Metallography serta pengujian kandungan delta ferrite dan pengujian Scanning Electron Microscope (SEM). Dari pengujian tersebut diketahui struktur mikro, komposisi kimia logam las dan distribusi kekerasan. Hasil pengujian kekerasan pada spesimen yang menggunakan kawat ERNiCr-3 nilai tertinggi ada pada bagian logam las dan pada spesimen yang menggunakan kawat ER309 nilai kekerasan tertinggi ada pada bagian HAZ T91. Pada struktrur mikro kedua spesimen dengan dua kawat las terbentuk presipitasi karbida kromium dengan jumlah yang kecil. ================================================================================================ Dissimilar Metal Welding (DMW) is one method for connecting different Metals, for example, as stainless steel (SS) connectors with low carbon alloy steel. This type of Metal kettle is usually used in special power plants in the boiler tube section. This is because boiler tubes work at different temperatures and pressures that will affect the use of the materials used. Austenite which has excellent corrosion resistance at high temperatures and pressures, and in parts with higher temperatures used alloy steel with the economic value of the material. However, in DMW, there is a difference between the chemical composition of the material that occurs in the fusion line, which is caused by different mechanical and microstructure so that it will be susceptible to change. One of the steps in reducing the problems needed in DMW is to predict the chemical composition of Welding Metals where the chemical composition can be regulated by selecting Welding wires that are really in accordance with the standards used In this study different Metals were welded between SS347HTB and low alloy carbon steel (T91) with variations in filler Metal ER309 and ERNiCr-3, where the voltage and current of Welding were the same. This Welding variation uses the arc Welding tungsten gas method (GTAW). After the Welding process is carried out damage testing, Metallurgical testing and SEM-EDS testing. Tests carried out in this study were hardness testing with microvickers, Metallographic testing and ferrite delta testing and Scanning Electron Microscope (SEM) testing. From these tests it is known microstructure, chemical composition of weld Metal and hardness distribution. Test results on specimens using the highest value ERNiCr-3 wire on weld Metal parts and on specimens using ER309 wire the highest hardness value on the HAZ T91 section. In the second specimen microstructure with two Welding wires, small amounts of chromium carbide are formed