Effect of Mn Content on Microstructure and Mechanical Properties of Weld Metal During High Heat Input Welding Processes

2017 ◽  
Vol 26 (6) ◽  
pp. 2947-2953 ◽  
Author(s):  
F. Y. Song ◽  
M. H. Shi ◽  
P. Wang ◽  
F. X. Zhu ◽  
R. D. K. Misra
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Heat Input ◽  
High Heat ◽  
Microstructure And Mechanical Properties ◽  
High Heat Input ◽  
Mn Content ◽  
Welding Processes

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.

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.

scholarly journals Mechanical Properties and Microstructures of High Heat Input Welded Tandem EGW Joint in EH36-TM Steel

2007 ◽  
Vol 25 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Hong-Chul Jeong ◽  
Young-Hwan Park ◽  
Young-Ho An ◽  
Jong-Bong Lee
Keyword(s):  
Mechanical Properties ◽  
Heat Input ◽  
High Heat ◽  
High Heat Input

scholarly journals Effect of Welding Thermal Cycles on Microstructure and Mechanical Properties of Multi-Strand Composite Welding Wire Welded Joints of High Nitrogen Austenitic Stainless Steel

2019 ◽  
Author(s):  
jianguo Li ◽  
Huan Li ◽  
Yu Liang ◽  
Pingli Liu ◽  
Lijun Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Welded Joints ◽  
Heat Input ◽  
Weld Seam ◽  
High Heat ◽  
High Nitrogen ◽  
Welding Wire ◽  
Delta Ferrite ◽  
High Heat Input

A multi-strand composite welding wire was applied to join high nitrogen austenitic stainless steel, and microstructures and mechanical properties were investigated. The electrical signals demonstrate that the welding process using a multi-strand composite welding wire is highly stable. The welded joints are composed of columnar austenite and dendritic ferrite and welded joints obtained under high heat input and cooling rate have a noticeable coarse-grained heat-affected zone and larger columnar austenite in weld seam. Compared with welded joints obtained under the high heat input and cooling rate, welded joints have the higher fractions of deformed grains, high angle grain boundaries, Schmid factor and the lower dislocation density under the low heat input and cooling rate, which indicate a lower tensile strength and higher yield strength. The rotated goss (GRD) orientation of a thin plate and the cube (C) orientation of a thick plate are obvious after welding, but the S orientation at 65° sections of Euler’s space is weak. The δ-ferrite was studied based on the primary ferrite solidification mode. It is observed that low heat input and high cooing rate result in the increasing of δ-ferrite and high dislocation density was obtained in grain boundaries of δ-ferrite. M23C6 precipitates due to low cooling rate and heat input in weld seam and deteriorates the elongation of welded joints. The engineering stress-strain curves also show the low elongation and tensile strength of welded joints under low heat input and cooling rate, which is mainly caused by the high fraction of δ-ferrite and the precipitation of M23C6.

Improvement of Weld Metal Toughness in High Heat Input Electro-Slag Welding of Low Carbon Steel

2009 ◽  
Vol 53 (3-4) ◽  
pp. R57-R63 ◽  
Author(s):  
Yasushi Kitani ◽  
Rinsei Ikeda ◽  
Moriaki Ono ◽  
Kenji Ikeuchi
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Heat Input ◽  
Low Carbon Steel ◽  
High Heat ◽  
Low Carbon ◽  
High Heat Input

scholarly journals In-situ observation on the influences of Ti on phase transformation of weld metal processed by high-heat input welding

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402096228
Author(s):  
Song Fengyu ◽  
Yao Lingzhen ◽  
Li Yanmei
Keyword(s):  
Phase Transformation ◽  
Weld Metal ◽  
Heat Input ◽  
High Heat ◽  
Transformation Process ◽  
In Situ Observation ◽  
High Heat Input ◽  
Bainite Microstructure ◽  
Ti Content

The in-situ observation of the phase transformation processes of weld metal during high-heat input welding were carried out by a high temperature laser confocal microscope. The influences of Ti content on the phase transformation process were investigated. It was found that the Ti inclusions could act as the nucleation sites for α→γ transformation during the heating stage of welding thermo cycle and inhibit the growth of austenite grains. The number of inclusions was increased with increasing Ti content. During the cooling stage of welding thermo cycle, the inclusions could induce the nucleation of acicular ferrites when the Ti content was below 0.078%. With increasing Ti content, more acicular ferrites collided with each other and restricted their further growth. When the Ti content was increased up to 0.115%, a proportion of Ti atoms were dissolved in the matrix, which increased the hardenability and thus generated the lath bainite microstructure instead of acicular ferrite.

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