scholarly journals Pengujian Merusak Pada Kualifikasi Prosedur Las Plat Baja Karbon SA-36 dengan Proses Pengelasan SMAW Berdasarkan Standar ASME Section IX

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Amelia Rahmatika ◽  
Eko Sutarto ◽  
Agus C. Arifin
Keyword(s):  
Base Metal ◽  
Pressure Vessel ◽  
Arc Welding ◽  
Acceptance Criteria ◽  
Metal Arc Welding ◽  
Welding Procedure

Spesifikasi Prosedur Las (Welding Procedure Specification/WPS) merupakan dokumen tertulis yang menjelaskan prosedur pengelasan dan memberikan arahan pada juru las untuk menghasilkan mutu produk las sesuai dengan kode dan standar yang telah ditentukan. WPS merupakan hal yang sangat penting dalam proses pengelasan, sehingga perlu proses kualifikasi. WPS dapat dinyatakan terkualifikasi jika memiliki rekaman kualifikasi prosedur (Procedure Qualification Record/PQR). Tahapan kualifikasi WPS dan PQR adalah pembuatan spesimen, pengelasan spesimen, pengujian dan pemeriksaan hasil pengujian spesimen. Penelitian ini bertujuan untuk melakukan pengujian merusak yaitu pengujian tarik dan pengujian tekuk (bending) pada prosedur las plat baja karbon rendah SA-36 dengan proses pengelasan SMAW (Shield Metal Arc Welding). Jenis pengujian dan jumlah spesimen mengacu pada standar ASME BPVC (Boiler Pressure Vessel) Section IX. Total jumlah spesimen uji adalah 6 (enam) spesimen dengan rincian yaitu 2 (dua) spesimen uji tarik, 2 (dua) spesimen uji face bend, dan 2 (dua) spesimen uji root bend. Preparasi spesimen pengujian tarik mengacu pada QW-462.1.(a) dan preparasi spesimen pengujian bending mengavcu pada QW-463.1.(a) standar ASME BVPC Section IX. Berdasarkan hasil pengujian tarik spesimen, didapatkan kekuatan tarik maksimum rata-rata sebesar 439,75 MPa dengan lokasi patahan berada di daerah logam dasar (base metal). Mengacu pada syarat keberterimaan (acceptance criteria) uji tarik menurut QW-153.1. standar ASME BPVC Section IX, maka spesimen tersebut dinyatakan lulus uji. Berdasarkan hasil pengujian bending, terdapat cacat terbuka (open discontinuity) maksimum sebesar 1,5 mm. Dengan adanya cacat terbuka

Welding Procedure Development for Welding of High Strength Carbon Steel Cladded with Austenitic Stainless Steel 316L by Using Overmatching Filler Metal

2013 ◽  
Vol 545 ◽  
pp. 182-187 ◽  
Author(s):  
Nusara Tiyasri ◽  
Bovornchok Poopat
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Arc Welding ◽  
Filler Metal ◽  
Small Diameter ◽  
High Strength ◽  
Metal Arc Welding ◽  
Welding Procedure

This work aims to develop welding procedure for small diameter longitudinal welded clad pipe made from clad plate. High strength carbon steel base metal bonded with 316L stainless steel clad layer was used in this study. The dissimilar materials at the weld joint and accessibility limitation of small diameter present difficulty in welding process selection to achieve weld soundness. The joint and welding se¬quence are designed to avoid solidification cracking. Nickel base over matching filler is used on the clad side. Typical joint configuration is double V groove weld without clad peel back to minimize the number of passes inside the pipe. Firstly, welding is done on the carbon steel side by using Shielded Metal Arc Welding (SMAW) and Submerged Arc Welding (SAW) with carbon steel electrodes. Then, welding on the clad side is done by using ERNiCrMo-3 filler metal. Two different procedures for the clad side are studied. The first procedure is to weld the clad side by using Gas Tungsten Arc Welding (GTAW) and Gas Metal Arc Welding pulse current (GMAW-pulse) and another procedure is to weld the clad side by using the SAW procedure. Hot cracking was observed in the case of SAW procedure at the clad weld centerline due to high heat input and high level of dilution. Mechanical properties and microstructure are evaluated. Clad weld by use of GTAW and GMAW-pulse could give sound weld metal. The tensile and yield strength of all weld metal were found to be greater than that of base metal and 100% shear failures were observed. Charpy impact energy of weld and HAZ at -10°C was found to be over 100 joules. Hardness of weld and HAZ area are surveyed over the weld cross section to determine local hardening. Additionally intergranular corrosion testing was carried out on the clad weld side and then bend testing was done. No crack was observed. Therefore, GTAW and GMAW-pulse clad weld procedure could give required properties according to clad line pipe standard, reduce cost of production and increase productivity compared to the peel back method.

Gas metal arc welding of XPF800 steel for automotive industry: Microstructural evaluation and mechanical properties investigation

2021 ◽  
pp. 146442072110567
Author(s):  
Emre Korkmaz ◽  
Cemal Meran
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Automotive Industry ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Charpy Impact ◽  
Optical Microscope ◽  
Metal Arc Welding ◽  
Heat Affected Zone Softening

In this study, the effect of gas metal arc welding on the mechanical and microstructure properties of hot-rolled XPF800 steel newly produced by TATA Steel has been investigated. This steel finds its role in the automotive industry as chassis and seating applications. The microstructure transformation during gas metal arc welding has been analyzed using scanning electron microscope, optical microscope, and energy dispersive X-ray spectrometry. Tensile, Charpy impact, and microhardness tests have been implemented to determine the mechanical properties of welded samples. Acceptable welded joints have been obtained using heat input in the range of 0.28–0.46 kJ/mm. It has been found that the base metal hardness of the welded sample is 320 HV0.1. On account of the heat-affected zone softening, the intercritical heat-affected zone hardness values have diminished ∼20% compared to base metal.

Metal Transfer in Double-Electrode Gas Metal Arc Welding

2007 ◽  
Vol 129 (6) ◽  
pp. 991-999 ◽  
Author(s):  
Kehai Li ◽  
YuMing Zhang
Keyword(s):  
Base Metal ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
High Melting ◽  
High Productivity ◽  
Spray Transfer ◽  
Metal Arc Welding ◽  
Double Electrode ◽  
Melting Current

Gas metal arc welding (GMAW) is the most widely used process for metal joining because of its high productivity and good quality, but analysis shows that the fundamental characteristic restricts conventional GMAW from further increasing the welding productivity. A novel GMAW process, refereed to as double-electrode GMAW or DE-GMAW, thus has been developed to make it possible to increase the melting current while the base metal current can still be controlled at a desired level. This fundamental change provides an effective method to allow manufacturers to use high melting currents to achieve high melting speed and low base metal heat input. A series of experiments have been conducted to uncover the basic characteristics of this novel process. Results obtained from analyses of high-speed image sequences and recorded current signals suggest that DE-GMAW can lower the critical current for achieving the desired spray transfer, shift the droplet trajectory, reduce the diameter of the droplet, and increase the speed and (generation) rate of the droplets.

scholarly journals Shielded Metal Arc and Thermite Welding Effect to Residual Stress, Hardness and Crack of R54-Rail Weld Joint

2020 ◽  
Vol 55 (4) ◽  
Author(s):  
Yurianto ◽  
Gunawan Dwi Haryadi ◽  
Sri Nugroho ◽  
Sulardjaka ◽  
Susilo Adi Widayanto
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Welding Process ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Crack Susceptibility

The heating and cooling at the end of the welding process can cause residual stresses that are permanent and remain in the welded joint. This study aims to evaluate the magnitude and direction of residual stresses on the base metal and heat-affected zone of rail joints welded by the manual shielded metal arc and thermite welding. This research supports the feasibility of welding for rail. The material used in this study is the R-54 rail type, and the procedure used two rail samples of one meter long each, welded using manual shielded metal arc welding and thermite welding. The base metal and heat-affected zone of the welded joints were scanned with neutron ray diffraction. The scan produces a spectrum pattern and reveals the direction of the residual stress along with it. We found the strain value contained in both types of welded joints by looking at the microstrain values, which we obtained using the Bragg equation. The results show that the magnitude and direction of the residual stress produced by manual shielded metal arc welding and thermite welding are not the same. Thermite welding produces lower residual stress (lower crack susceptibility) than manual shielded metal arc welding. The melt's freezing starts from the edge to the center of the weld to create random residual stresses. The residual stress results of both the manual shielded metal arc welding and thermite welding are still below the yield strength of the base metal.

A52M/SA52 Dissimilar Metal RPV Repair Weld: Experimental Evaluation and Post-Weld Characterizations

2020 ◽  
Author(s):  
Iikka Virkkunen ◽  
Mikko Peltonen ◽  
Henrik Sirén ◽  
Pekka Nevasmaa ◽  
Caitlin Huotilainen ◽  
...  
Keyword(s):  
Pressure Vessel ◽  
Arc Welding ◽  
Nuclear Power ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Reactor Pressure Vessel ◽  
Cold Metal Transfer ◽  
Metal Arc Welding ◽  
Cold Metal ◽  
Reactor Pressure

Abstract Aging management of the existing fleet of nuclear power plants is becoming an increasingly important topic, especially as many units are approaching their design lifetimes or are entering long-term operation. As these plants continue to age, there is an increased probability for the need of repairs due to extended exposure to a harsh environment. It is paramount that qualified and validated solutions are readily available. A repair method for a postulated through cladding crack into the low alloy steel of a nuclear power plant’s reactor pressure vessel has been investigated in this study. This paper is part of larger study that evaluates the current possibilities of such repair welds. The present paper documents the weld-trials and method selection. A parallel paper describes numerical simulations and optimization of weld parameters. The presented weld-trial represents a case where a postulated crack has been excavated and repaired using a nickel base Alloy 52M filler metal by gas metal arc welding-cold metal transfer with a robotic arm. A SA235 structural steel has been used as a base material in this weld-trial. No pre-heating or post-weld heat treatment will be applied, as it would be nearly impossible to apply these treatments in a reactor pressure vessel repair situation. While Alloy 52M presents good material properties, in terms of resistance to environmentally assisted degradation mechanisms, such as primary water stress corrosion cracking, it is notoriously difficult to weld. Some difficulties and challenges during welding include a sluggish weld puddle, formation of titanium and/or aluminium oxides and its susceptibility to lack of fusion defects and weld metal cracking, such as ductility dip cracking and solidification cracking. Moreover, gas metal arc welding-cold metal transfer is not traditionally used in the nuclear industry. Nonetheless, it presents some interesting advantages, specifically concerning heat input requirements and automation possibilities, as compared to traditional welding methods. The mechanical properties, in terms of indentation hardness, and microstructure of a weld-trial sample have been evaluated in this study. The fusion boundary and heat affected zone were the main areas of focus when evaluating the mechanical and microstructural properties. Detailed microstructural characterization using electron backscatter diffraction and nanoindentation were performed across the weld interface. Based on these results, the gas metal arc welding cold metal transfer is seen as a potential high-quality weld method for reactor pressure vessel repair cases.

scholarly journals Modus Pelunakan dan Pengerasan HAZ pada Manual GMAW Welded Joint

ROTASI ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 127
Author(s):  
Yurianto Yurianto ◽  
Pratikto Pratikto ◽  
Rudy Soenoko ◽  
Wahyono Suprapto
Keyword(s):  
Arc Welding ◽  
Welded Joint ◽  
State Of The Art ◽  
Gas Metal Arc Welding ◽  
Metal Arc Welding ◽  
Heat Treated ◽  
Welding Procedure

Las manual gas metal arc welding banyak digunakan dalam industri manufaktur konvensional. Akhir proses pengelasan menghasilkan produk las yang diinginkan. Pada baja dengan tebal dan jenis yang sama, dan metode pengelasan yang sama tetapi operator berbeda menghasilkan kekuatan las yang berbeda. Keseragaman produk las antara satu dan operator lain dapat diperoleh dengan welding procedure specification. Namun prosedur ini tidak menjamin kekuatan sambungan sama meskipun operator berbeda. Kekuatan daerah terpengaruh panas tergantung pada parameter las yang digunakan seperti diameter elektroda; arus listrik; tegangan listrik, kecepatan pengelasan; logam tebal dan panas masuk. Selain itu, perlu dipertimbangkan unsur kimia baja yang dilas. Parameter pengelasan akan mempengaruhi dimensi daerah terpengaruh panas. Semakin lebar daerah terpengaruh panas akan menurunkan kekuatan sambungan las. Pernyataan masalah dalam penelitian ini adalah "bagaimana menurunkan dimensi daerah terpengaruh panas yang dipengaruhi oleh proses pembekuan logam las." State of the art dari penelitian ini adalah analisis pelunakan daerah terpengaruh panas dengan melibatkan pembekuan logam las. Tujuan dari penelitian ini adalah untuk mencari penyebab terjadinya pelunakan dalam daerah terpengaruh panas sambungan las gas metal arc welding manual. Hasil penelitian adalah kekerasan standard dan heat treated welded joint. Parameter perlakuan panas untuk mendapatkan kekerasan HAZ tertinggi.

scholarly journals Twin-Wire Pulsed Tandem Gas Metal Arc Welding of API X80 Steel Linepipe

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Wenhao Wu ◽  
Ming Zhao ◽  
Haiyan Wang ◽  
Yanxia Zhang ◽  
Tong Wu
Keyword(s):  
Corrosion Resistance ◽  
Weld Metal ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Arc Welding ◽  
Production Efficiency ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Metal Arc Welding ◽  
X80 Steel

Twin-Wire Pulsed Tandem Gas Metal Arc Welding process with high welding production efficiency was used to join the girth weld seam of API X80 steel linepipe of 18.4 mm wall thickness and 1422 mm diameter. The macrostructure, microstructure, hardness, and electrochemical corrosion behavior of welded joints were studied. Effects of temperature and Cl− concentration on the corrosion behavior of base metal and weld metal were investigated. Results show that the welded joint has good morphology, mechanical properties, and corrosion resistance. The corrosion resistance of both the base metal and the weld metal decreases with increasing temperature or Cl− concentration. In the solution with high Cl− concentration, the base metal and weld metal are more susceptible to pitting. The corrosion resistance of the weld metal is slightly lower than that of the base metal.

Investigation of Transport Phenomena in Three-Dimensional Gas Metal Arc Welding of Thick Metals

2007 ◽  
Author(s):  
Jun Zhou ◽  
Mohammad S. Davoud ◽  
Hai-Lung Tsai
Keyword(s):  
Base Metal ◽  
Weld Pool ◽  
Arc Welding ◽  
Transport Phenomena ◽  
Gas Metal Arc Welding ◽  
Heat Diffusion ◽  
Liquid Region ◽  
Weld Penetration ◽  
Melt Flow ◽  
Metal Arc Welding

Arc welding is generally used to join thick metals in many engineering applications. However, poor penetration often occurs due to arc heat diffusion into the base metal. Hence, arc welding of thick metals normally requires grooving and/or preheating of the base metal and sometimes requires multiple passes for very thick metals or metals with high conductivity, such as aluminum alloys. In gas metal arc welding of thick metals with grooves and preheating, complicated melt flow and heat transfer are caused by the combined effect of droplet impingement, gravity, electromagnetic force, surface tension, and plasma arc pressure. Understanding these complicated transport phenomena involved in the welding process is critical in improving the penetration depth and weld quality. In this study, mathematical models and associated numerical techniques have been developed to study the effects of grooves and preheating on melt flow, diffusion of species, and weld penetration in gas metal arc welding of thick metals. Complex melt flow, transient weld pool shape and distributions of temperature and species in the weld pool are calculated. The continuum formation is adopted to handle liquid region, mushy zone and solid region. VOF technique is used to handle transient deformed shape of weld pool surface. The preliminary results show both grooves and preheating have important effects on the melt flow in weld pool and the weld penetration. Computer animations showing the evolutions of temperature; melt flow; and the interaction between droplets and weld pool will be presented.

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