Development of Welding Materials for High Heat Input Welding Compatible with Thick Steel Plates of 460 MPa Yield Point Class for Very Large Container Ships

2010 ◽  
Vol 54 (1-2) ◽  
pp. R35-R41 ◽  
Author(s):  
Yuuji Hashiba ◽  
Kiyohito Sasaki ◽  
Tadashi Kasuya ◽  
Takehiro Inoue ◽  
Yuuji Funatsu
Keyword(s):  
Yield Point ◽  
Heat Input ◽  
High Heat ◽  
Steel Plates ◽  
High Heat Input ◽  
Thick Steel ◽  
Large Container ◽  
Point Class ◽  
Welding Materials

scholarly journals Mechanism of Improving Heat-Affected Zone Toughness of Steel Plate with Mg Deoxidation after High-Heat-Input Welding

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 162 ◽  
Author(s):  
Longyun Xu ◽  
Jian Yang ◽  
Joohyun Park ◽  
Hideki Ono
Keyword(s):  
Heat Input ◽  
Steel Plate ◽  
High Heat ◽  
Steel Plates ◽  
In Situ Observation ◽  
Austenite Grain ◽  
Micron Size ◽  
High Heat Input ◽  
Mg Content ◽  
Haz Toughness

In the present study, the mechanism of improving HAZ toughness of steel plate with Mg deoxidation after the simulated welding with the heat input of 400 kJ/cm was investigated through in situ observation, characterization with SEM-EDS and TEM-EDS, and thermodynamic calculation. It was found that intragranular acicular ferrite (IAF) and polygonal ferrite (PF) contributed to the improvements of HAZ toughness in steels with Mg deoxidation. With the increase of Mg content in steel, the oxide in micron size inclusion was firstly changed to MgO-Ti2O3, then to MgO with the further increase of Mg content in steel. The formation of nanoscale TiN particles was promoted more obviously with the higher Mg content in the steel. The growth rates of austenite grains at the high-temperature stage (1400~1250 °C) during the HAZ thermal cycle of steels with conventional Al deoxidation and Mg deoxidation containing 0.0027 and 0.0099 wt% Mg were 10.55, 0.89, 0.01 μm/s, respectively. It was indicated that nanoscale TiN particles formed in steel with Mg deoxidation were effective to inhibit the growth of austenite grain. The excellent HAZ toughness of steel plates after welding with a heat input of 400 kJ/cm could be obtained by control of the Mg content in steel to selectively promote the formation of IAF or retard the growth of austenite grain.

scholarly journals Higher-Strength Steels Specially Processed for High Heat Input Welding

1985 ◽  
Vol 1 (04) ◽  
pp. 222-237
Author(s):  
I. L. Stern ◽  
M. Wheatcroft ◽  
D. Y. Ku
Keyword(s):  
Heat Affected Zone ◽  
Heat Input ◽  
Large Scale ◽  
Welding Process ◽  
High Heat ◽  
Coast Guard ◽  
Steel Plates ◽  
Small Scale ◽  
Bulge Testing ◽  
High Heat Input

ABS Grade EH36 steel plates, specially formulated and produced with advanced metallurgical techniques, are shown to have a significantly greater resistance to weld heat-affected zone (HAZ) degradation that conventional EH36 steel. Welds made in these steels with the electroslag welding process at high heat input rates retained adequate toughness in the heat-affected zone at --4°F (-20°C); similar welds in conventional EH36 steel plate exhibit excessive HAZ toughness loss. This effect was confirmed on the basis of small-scale Charpy V-notch and large-scale explosion bulge testing. In view of their superior resistance to HAZ degradation, the steels should also be useful for applications where HAZ degradation is of particular concern, such as for American Bureau of Shipping (ABS), U.S. Coast Guard, and International Maritime Organization (IMO) weld requirements for liquefied gas carriers.

scholarly journals Improvement of Heat-Affected Zone Toughness of Steel Plates for High Heat Input Welding by Inclusion Control with Ca Deoxidation

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 946 ◽  
Author(s):  
Ruizhi Wang ◽  
Jian Yang ◽  
Longyun Xu
Keyword(s):  
Heat Affected Zone ◽  
Heat Input ◽  
High Heat ◽  
Steel Plates ◽  
Number Density ◽  
High Heat Input ◽  
Intragranular Acicular Ferrite ◽  
Average Size ◽  
Inclusion Control ◽  
Haz Toughness

The characteristics of inclusions and microstructure in heat-affected zones (HAZs) of steel plates with Ca deoxidation after high heat input welding of 400 kJ·cm−1 were investigated through simulated welding experiments and inclusions automatic analyzer systems. Typical inclusions in HAZs of steels containing 11 ppm and 27 ppm Ca were recognized as complex inclusions with the size in the range of 1~3 μm. They consisted of central Al2O3 and peripheral CaS + MnS with TiN distributing at the edge (Al2O3 + CaS + MnS + TiN). With increasing Ca content in steel, the average size of inclusions decreased from 2.23 to 1.46 μm, and the number density increased steadily from 33.7 to 45.0 mm−2. Al2O3 + CaS + MnS + TiN complex inclusions were potent to induce the formation of intragranular acicular ferrite (IAF). Therefore, the HAZ toughness of steel plates after high heat input welding was improved significantly by utilizing oxide metallurgy technology with Ca deoxidation.

Effect of Weld HAZ Softening on Tensile Strength of Welded Joint with Weld HAZ Softening

2008 ◽  
Vol 580-582 ◽  
pp. 589-592 ◽  
Author(s):  
Gyu Baek An ◽  
Seong Kil Nam ◽  
Tae Won Jang
Keyword(s):  
Tensile Strength ◽  
Welded Joint ◽  
Welding Process ◽  
Steel Structure ◽  
High Heat ◽  
Steel Plates ◽  
Shipbuilding Industry ◽  
High Productivity ◽  
High Heat Input ◽  
Thick Steel

In recent time there are vigorous requirements for the use of thick steel plate in various industrial fields, including shipbuilding industry. Especially, application of TMCP steel plates on steel structure is progressively increasing now. Welding process with high heat input is necessary to be used in thick steel assembly for the purpose of the high productivity. However, HAZ softening of TMCP steel plates has a possibility to reduce the strength of welded joint. In this study, therefore, the tensile strength of TMCP weldments, having softened HAZ, was examined using the numerical calculation and experiments.

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.

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