scholarly journals The influence of heat input on the toughness and fracture mechanism of surface weld metal

2018 ◽  
Vol 13 ◽  
pp. 2216-2220 ◽  
Author(s):  
O. Popović ◽  
R. Prokić Cvetković ◽  
Lj. Radović ◽  
Z. Burzić ◽  
D. Arsić
Keyword(s):  
Weld Metal ◽  
Heat Input ◽  
Fracture Mechanism

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.

Effects of oxygen content on microstructure and impact toughness of high heat input flux-cored wire weld metals

2018 ◽  
Vol 115 (4) ◽  
pp. 410
Author(s):  
Fengyu Song ◽  
Yanmei Li ◽  
Ping Wang ◽  
Fuxian Zhu
Keyword(s):  
Grain Size ◽  
Impact Toughness ◽  
Weld Metal ◽  
Oxygen Content ◽  
Heat Input ◽  
High Heat ◽  
Cored Wire ◽  
Weld Metals ◽  
High Heat Input ◽  
The Impact

Three weld metals with different oxygen contents were developed. The influence of oxygen contents on the microstructure and impact toughness of weld metal was investigated through high heat input welding tests. The results showed that a large number of fine inclusions were formed and distributed randomly in the weld metal with oxygen content of 500 ppm under the heat input condition of 341 kJ/cm. Substantial cross interlocked acicular ferritic grains were induced to generate in the vicinity of the inclusions, primarily leading to the high impact toughness at low temperature for the weld metal. With the increase of oxygen content, the number of fine inclusions distributed in the weld metal increased and the grain size of intragranular acicular ferrites decreased, which enhanced the impact toughness of the weld metal. Nevertheless, a further increase of oxygen content would contribute to a great diminution of the austenitic grain size. Following that the fraction of grain boundary and the start temperature of transformation increased, which facilitated the abundant formation of pro-eutectoid ferrites and resulted in a deteriorative impact toughness of the weld metal.

Influence of Nitrogen and Heat Input on Weld Metal of Gas Tungsten Arc Welded High Nitrogen Steel

2007 ◽  
Vol 14 (5) ◽  
pp. 259-262 ◽  
Author(s):  
Lin ZHAO ◽  
Zhi-ling TIAN ◽  
Yun PENG ◽  
Yan-chang QI ◽  
Yan-jie WANG
Keyword(s):  
Weld Metal ◽  
Heat Input ◽  
High Nitrogen Steel ◽  
High Nitrogen ◽  
Gas Tungsten Arc ◽  
Nitrogen Steel ◽  
Gas Tungsten

High Heat Input Welding of 12Cr-6Ni-2.5Mo Supermartensitic Stainless Steel

2003 ◽  
Author(s):  
Ragnhild Aune ◽  
Hans Fostervoll ◽  
Odd Magne Akselsen
Keyword(s):  
Weld Metal ◽  
Stainless Steels ◽  
Heat Affected Zone ◽  
Heat Input ◽  
High Heat ◽  
Maximum Heat ◽  
Final Microstructure ◽  
Girth Welding ◽  
High Heat Input ◽  
Longitudinal Seam

In conventional welding of 13% Cr supermartensitic stainless steels, the normal microstructure that forms on cooling is martensite. Although high heat input tends to give a certain coarsening of the final microstructure, the eventual accompanying loss in toughness is not known. The present study was initiated to examine the effect of heat input on weld metal and heat affected zone mechanical properties of a 12Cr-6Ni-2.5Mo grade. The results obtained showed that the notch toughness is low (25 J) and independent of heat input for the weld metal, while it is reduced with increasing heat input for fusion line and the heat affected zone locations. Subsequent post weld heat treatment gave a substantial increase in toughness for all notch locations. Based on these results, indications are that a specified maximum heat input is not applicable in welding of supermartensitic stainless steels, allowing more production efficient techniques to be used, both in longitudinal seam and girth welding.

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.

Influence of Argon-Nitrogen Gas to Balance the Microstructure in the Welding of Super Duplex Stainless Steel

2016 ◽  
Vol 836 ◽  
pp. 165-172
Author(s):  
Suheni
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Heat Input ◽  
Oil And Gas ◽  
Austenite Phase ◽  
Super Duplex Stainless Steel ◽  
Shielding Gas ◽  
Input Variables ◽  
Protective Gas

Super duplex stainless steel is steel that has a corrosion resistance and good mechanical strength so that used in industry especially in oil and gas and petrochemical industry. In use in the field is often used for the connection process by welding methods. To produce good welds, it should be noted that the welding procedures and parameters used , especially the heat input. In this study is used the heat input variables shielding gas composition to determine how much influence on the balance of ferrite - austenite phase structure in the weld stainless steels SAF 2507 super duplex with tungsten inert gas welding method (TIG). Heat input varied by applying different welding speed 1,3,4 and 5 mm /sec while the shielding gas is used 100 % argon, 98 % argon + 2 % nitrogen and 95 % argon + 5 % nitrogen. The result showed that at different welding speeds generated depth and width of the weld metal which is different. Likewise the use of protective gas will produce a different ratio wide and deep of weld metal which is different. By using protective gas 95 % argon + 5 % nitrogen squeak - ausenit phase, resulting in weld metal that is relatively balanced than others. On a slow welding in addition to produce a large heat input also produces weld metal hardness at high and affect the growth of the austenite phase. The higher the heat input ( 2,280 kJ / mm ) , the lower the austenite phase in the weld metal.

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