scholarly journals Influence of the Heat Input on the Dendritic Solidification Structure and the Mechanical Properties of 2.25Cr-1Mo-0.25V Submerged-Arc Weld Metal

2021 ◽  
Author(s):  
Hannah Schönmaier ◽  
Ronny Krein ◽  
Martin Schmitz-Niederau ◽  
Ronald Schnitzer
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Heat Input ◽  
Stress Rupture ◽  
Pressure Vessels ◽  
Rupture Time ◽  
Solidification Structure ◽  
Welding Parameters ◽  
Austenite Grain Size ◽  
Submerged Arc

AbstractThe alloy 2.25Cr-1Mo-0.25V is commonly used for heavy wall pressure vessels in the petrochemical industry, such as hydrogen reactors. As these reactors are operated at elevated temperatures and high pressures, the 2.25Cr-1Mo-0.25V welding consumables require a beneficial combination of strength and toughness as well as enhanced creep properties. The mechanical properties are known to be influenced by several welding parameters. This study deals with the influence of the heat input during submerged-arc welding (SAW) on the solidification structure and mechanical properties of 2.25Cr-1Mo-0.25V multilayer metal. The heat input was found to increase the primary and secondary dendrite spacing as well as the bainitic and prior austenite grain size of the weld metal. Furthermore, it was determined that a higher heat input during SAW causes an increase in the stress rupture time and a decrease in Charpy impact energy. This is assumed to be linked to a lower number of weld layers, and therefore, a decreased amount of fine grained reheated zone if the multilayer weld metal is fabricated with higher heat input. In contrast to the stress rupture time and the toughness, the weld metal’s strength, ductility and macro-hardness remain nearly unaffected by changes of the heat input.

scholarly journals The Influence of Heat Input to Mechanical Properties and Microstructures of API 5L-X65 Steel Using Submerged Arc Welding Process

2019 ◽  
Vol 269 ◽  
pp. 01009 ◽  
Author(s):  
Suryana ◽  
Agus Pramono ◽  
Iskandar Muda ◽  
Ade Setiawan
Keyword(s):  
Mechanical Properties ◽  
Heat Input ◽  
Arc Welding ◽  
High Reliability ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Welding Parameters ◽  
X65 Steel ◽  
Api 5L X65 Steel ◽  
Submerged Arc

API 5L-X65 steel is the type of high strength low alloy (HSLA) steel, widely used in the manufacture of pipe. Submerged arc welding (SAW) is widely used for the fabrication of the pipe, the extent of use submerged arc welding caused it could be done automatically and high reliability. The results of the welding process will lead to differences and changes in the microstructure in heat affected zone (HAZ) and weld metal that will affect the mechanical properties of the output, so as to obtain good welding results required the selection of welding parameters accordingly. As the use of the heat input during welding is very important influence on the mechanical properties and microstructure of the weld. The purpose of this study to determine the effect of heat input on the microstructure, hardness and toughness of welds in submerged arc welding. Welding currents used were 200, 300, 400 and 500 Ampere with a voltage were used 25, 27 and 30 Volt. The results showed that the higher heat input will result in a growing area of HAZ region width and grain size increased. Highest hardness values are the results of the weld heat input with a low of 244.69 HVN caused by the rapid cooling rate of the weld area. The highest toughness values are the results of the highest heat input that was dominated by acicular ferrite phase.

Effect of Welding Thermal Cycle on the Microstructure and Mechanical Properties in Multi-Pass Submerged-Arc Welding

2011 ◽  
Vol 314-316 ◽  
pp. 1163-1166 ◽  
Author(s):  
Zhong Yi Chen ◽  
Yong Lin Ma ◽  
Shu Qing Xing
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Arc Welding ◽  
Thermal Cycle ◽  
Welded Joint ◽  
Submerged Arc Welding ◽  
Welding Parameters ◽  
Microstructure And Mechanical Properties ◽  
Welding Thermal Cycle ◽  
Submerged Arc

To research effect of welding thermal cycle on the microstructure and mechanical properties of welded joint, two pieces of 60mm thick plates were welded together using automatic submerged-arc welding (SAW) method with suitable welding parameters. After 17 passes welding, the microstructures and phases of the welded joint was carefully observed and analyzed by using a Carl Zeiss optical microscope in different zones of welded joint, and the surface micro-hardness of the welded joint was measured systematically by using microscopic-hardness tester Lycra. Afterwards, the mechanical properties of the weld metals were measured through stretching. Through a series of measurements and observations, the welding experiment results indicate that effect of welding thermal cycle on the microstructure and mechanical properties of welding joint is great, the grains of the bottom of the weld metal are certainty smaller and more uniform, and the bottom of the weld metal have more excellent mechanical properties.

scholarly journals Mechanical Properties of Weld Metal for Fire-Resistant Steel with Large Heat Input Submerged Arc Welding.

1996 ◽  
Vol 14 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Kazutoshi ICHIKAWA ◽  
Yukihiko HORII ◽  
Ryuichi MOTOMATSU ◽  
Masami YAMAGUCHI ◽  
Nobutaka YURIOKA
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Heat Input ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Resistant Steel ◽  
Large Heat ◽  
Submerged Arc ◽  
Fire Resistant Steel

scholarly journals On the impact of post weld heat treatment on the microstructure and mechanical properties of creep resistant 2.25Cr–1Mo–0.25V weld metal

2021 ◽  
Author(s):  
Hannah Schönmaier ◽  
Christian Fleißner-Rieger ◽  
Ronny Krein ◽  
Martin Schmitz-Niederau ◽  
Ronald Schnitzer
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Weld Metal ◽  
Elevated Temperatures ◽  
Stress Rupture ◽  
Pressure Vessels ◽  
Post Weld Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
The Impact ◽  
Weld Heat

AbstractCreep resistant low-alloyed 2.25Cr-1Mo-0.25V steel is typically applied in hydrogen bearing heavy wall pressure vessels in the chemical and petrochemical industry. For this purpose, the steel is often joined via submerged-arc welding. In order to increase the reactors efficiency via higher operating temperatures and pressures, the industry demands for improved strength and toughness of the steel plates and weldments at elevated temperatures. This study investigates the influence of the post weld heat treatment (PWHT) on the microstructure and mechanical properties of 2.25Cr-1Mo-0.25V multi-layer weld metal aiming to describe the underlying microstructure-property relationships. Apart from tensile, Charpy impact and stress rupture testing, micro-hardness mappings were performed and changes in the dislocation structure as well as alterations of the MX carbonitrides were analysed by means of high resolution methods. A longer PWHT-time was found to decrease the stress rupture time of the weld metal and increase the impact energy at the same time. In addition, a longer duration of PWHT causes a reduction of strength and an increase of the weld metals ductility. Though the overall hardness of the weld metal is decreased with longer duration of PWHT, PWHT-times of more than 12 h lead to an enhanced temper resistance of the heat-affected zones (HAZs) in-between the weld beads of the multi-layer weld metal. This is linked to several influencing factors such as reaustenitization and stress relief in the course of multi-layer welding, a higher fraction of larger carbides and a smaller grain size in the HAZs within the multi-layer weld metal.

Recommendations for Submerged Arc Spiral Welding With Optimized CTOD Properties

2018 ◽  
Author(s):  
Martin Liebeherr ◽  
Özlem E. Güngör ◽  
Nuria Sanchez ◽  
Hervé Luccioni ◽  
Nenad Ilic
Keyword(s):  
Weld Metal ◽  
Base Material ◽  
Welding Process ◽  
Experimental Program ◽  
Welding Parameters ◽  
Pipe Production ◽  
Filler Wire ◽  
Crack Tip Opening Displacement ◽  
Wide Range ◽  
Submerged Arc

Many pipe mills may not be familiar with a Crack Tip Opening Displacement (CTOD) requirement on the pipe seam weld, nor will they find easily relevant information in open literature. Influencing — and certainly not independent — factors are: welding parameters, base material and consumable selection. Out of these, the welding parameters such as heat input and cooling rate cannot be varied over a wide range during the pipe production, which means that the leverage is rather limited at the given welding process. The properties of the heat affected zone will be mainly affected by the base material, while the properties of the weld metal will be affected by both, base material and filler wire selection. In particular with respect to the weld metal properties it will be difficult to obtain general quantitative information. For example, a welding consumable supplier will readily provide the properties of the filler wires but would be unable to predict the changes caused by the dilution from any base material in the weld pool and specific welding procedures that may have been used. To support the pipe mills in the selection of the consumables for submerged arc welding, an experimental program was launched with the aim to provide recommendations on how to optimize CTOD toughness of the spiral weld seam. For this, a large number of welds were produced on 20 mm thick X70 coil samples, with eight different filler wire combinations, using a 2-wire (tandem) set-up for both the inside and outside weld. Welding parameters were kept constant. The welding program was applied to two different X70 steels to determine a potential influence of the micro-alloying elements, particularly Nb. The results show clearly that a careful consumable selection is required for obtaining acceptable CTOD toughness in the weld metal. Ni-Mo and Ti-B additions to the weld metal are found to be beneficial with both steel concepts. Mo addition alone both to the ID and OD welds was clearly not a suitable selection.

Cold Metal Transfer Welding of AA6061 to AA7075: Mechanical Properties and Corrosion

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Nilay Çömez ◽  
Hülya Durmuş
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Heat Input ◽  
Dissimilar Materials ◽  
Metal Transfer ◽  
Welding Parameters ◽  
Cold Metal Transfer ◽  
Cmt Welding ◽  
Mechanical Properties And Corrosion ◽  
Cold Metal

Cold metal transfer (CMT) welding provides many advantages for welding of dissimilar materials and thin sheets with its superior heat input control mechanism. In this study, AA6061 and AA7075 aluminum alloys were joined with CMT welding. The effect of welding parameters on hardness, tensile strength, and corrosion rate was investigated. The Tafel extrapolation method was carried out to determine the corrosion rates of AA6061 and AA7075 base metals and AA6061–AA7075 joints. Increasing heat input was found to be detrimental for both mechanical properties and corrosion resistance. The outcomes showed that CMT welding produces adequate joints of AA6061–AA7075 in terms of mechanical properties and corrosion resistance, favorably with welding parameters that provide low heat input.

Comparison of Hardness and Microstructures Produced Using GMAW and Hot-Wire TIG Mechanized Welding of High Strength Steels

2014 ◽  
Author(s):  
A. R. H. Midawi ◽  
E. B. F. Santos ◽  
A. P. Gerlich ◽  
R. Pistor ◽  
M. Haghshenas
Keyword(s):  
Weld Metal ◽  
Deposition Rate ◽  
Heat Input ◽  
Gas Metal Arc Welding ◽  
High Strength Steels ◽  
Travel Speed ◽  
Pressure Vessels ◽  
High Deposition Rate ◽  
Hot Wire ◽  
Wire Feed

For high productivity weld fabrication, gas metal arc welding (GMAW) is typically used since it offers a combination of high deposition rate and travel speed. Recent advances in power supply technologies have increased the deposition rates in hot-wire tungsten inert gas (HW-TIG) welding, such that it is possible to achieve parameters which may be comparable to those used in GMAW for pressure vessels and some pipeline applications. However, these two processes have drastically different deposition efficiencies and heat input characteristics. The purpose of the present study is to examine GMAW and HW-TIG bead-on-plate deposits in terms of mechanical properties, deposition rate, and heat affected zone (HAZ) thermal cycles when identical travel speed and wire feed speeds are applied with a ER90S-G filler metal. The results demonstrate that HW-TIG can be applied with comparable travel and wire feed speeds to GMAW, while providing a more uniform weld bead appearance. Based on weld metal microhardness values, it is suggested the effective heat input is lower in HW-TIG compared to GMAW, since the average hardness of the weld metal is slightly higher.

Effect of the FCAW Welding Process and Post Weld Heat Treatment on the Properties and Microstructure of the Weld Joints of Heat Treated 4330V Steel

2015 ◽  
Vol 809-810 ◽  
pp. 437-442
Author(s):  
Jacek Górka ◽  
Michał Miłoszewski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Weld Metal ◽  
Heat Input ◽  
Large Diameter ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
High Toughness ◽  
Interpass Temperature ◽  
Weld Heat

4330V is a high strength, high toughness, heat treatable low alloy steel for application in the oil, gas and aerospace industries. It is typically used for large diameter drilling parts where high toughness and strength are required. The research describes the effect of preheat temperature, interpass temperature, heat input, and post weld heat treatment on strength, hardness, toughness, and changes to microstructure in the weld joint. Welding with the lower heat input and no post weld heat treatment resulted in optimal mechanical properties in the weld metal. Austempering at 400 °C resulted in optimal mechanical properties in the HAZ. Increasing preheat and interpass temperature from 340 °C to 420 °C did not improve Charpy V-notch values or ultimate tensile strength in the weld metal or heat affected zones. The higher temperature increased the width of the heat affected zone. Austempering at 400 °C reduced HAZ hardness to a level comparable to the base metal. Both tempering and austempering at 400 °C for 10 hours reduced toughness in the weld metal.

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