Research on High Heat Input Welding of the High Strength Electro-Gas Flux-Cored Wire Used for Large Storage Tank

2010 ◽  
Vol 638-642 ◽  
pp. 3699-3703
Author(s):  
Zhao Xia Qu ◽  
Han Qian Zhang
Keyword(s):  
Heat Input ◽  
Storage Tank ◽  
Welding Process ◽  
High Strength ◽  
High Heat ◽  
Welding Wire ◽  
Cored Wire ◽  
Gas Flux ◽  
Oil Storage ◽  
High Heat Input

Baosteel cooperated with the China’s welding consumable company and developed an electro-gas welding wire BH610-EG, which is a flux-cored welding wire and can match the high strength steel B610E. In this paper, the electro-gas welding technological tests are carried out by B610E with the thickness of 21 mm and 40 mm and BH610-EG wire with the diameter of 1.6 mm. And values of the heat input of electro-gas welding experiments are in the range of 80~100kJ/cm. The main conclusions can be obtained as follows: (1) In condition of high heat input, the electro-gas welding process using BH610-EG wire is very stable, the weld surface is good. (2) Various mechanical properties of the welded joints can meet the design requirements of the storage tanks. (3) The new developed electro-gas flux-cored welding wire BH610-EG can match with B610E steel and meet the requirement of high heat input of the crude oil storage tank.

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.

Impact Toughness Characteristics of SM570-TMC Steel Joint Using Welding Wire Containing 0.4% Nickel at Different Level of Heat Input

2020 ◽  
Vol 867 ◽  
pp. 117-124
Author(s):  
Herry Oktadinata ◽  
Winarto Winarto ◽  
Dedi Priadi ◽  
Eddy S. Siradj ◽  
Ario S. Baskoro
Keyword(s):  
Impact Toughness ◽  
Heat Input ◽  
High Heat ◽  
Optical Microscope ◽  
Butt Joint ◽  
Welding Wire ◽  
Steel Joint ◽  
Microstructure Observation ◽  
High Heat Input ◽  
The Impact

The study was conducted to evaluate the impact toughness of flux-cored arc welded of SM570-TMC steel joint under different heat inputs, 0.9 kJ/mm (low heat input) and 1.6 kJ/mm (high heat input). Welding wire containing 0.4%Ni was selected on this experiment. Multi-pass welds were performed on SM570-TMC steel plate of 16 mm in thickness with a single V-groove butt joint on flat position (1G). The evaluation consists of observations on microstructure using an optical microscope and SEM-EDS, and mechanical properties including tensile, microhardness Vickers and Charpy V-notch (CVN) impact test at temperatures of 25, 0 and-20 °C. Results showed that the impact toughness of the base metal (BM) was higher than the weld metal (WM) at all test temperatures. Hardness and impact toughness of WM at low heat input was observed higher than when applied a high heat input. The welded samples at low and high heat inputs had high of tensile strength, and the fracture seemly occurs on the BM. Microstructure observation showed that at a high heat input, larger grains and microsegregation were observed. It might affect on decreasing their impact property.

Progress in TMCP Technology and Expansion of Its Range of Application

2005 ◽  
Author(s):  
Yoichi Tanaka
Keyword(s):  
Heat Input ◽  
Heating Temperature ◽  
High Strength ◽  
High Heat ◽  
Commercial Application ◽  
Low Carbon ◽  
Controlled Processing ◽  
Fine Grain ◽  
High Heat Input ◽  
Effective Use

More than twenty years have passed since the development and commercialization of water-cooling-type TMCP (Thermo-Mechanical Controlled Processing) steel. At present, the technology is used in various areas as a reliable process. Features of TMCP steel are excellent weldability and toughness, which make it extremely useful as a tank material. This paper aims to contribute to the safety and workability improvement in the tank construction field as in other areas by the effective use of TMCP steel. The paper first describes the characteristics of material properties and workability of TMCP steel and the metallurgy to realize these characteristics. It then introduces a several examples of recent development in the application of TMCP technology. The use of TMCP steel realizes better toughness in high-heat-input welding, improved low-temperature toughness and sour gas resistance, in addition to reduced weld pre-heating temperature thanks to its low carbon content. Recently, because of its excellent characteristics, it has become possible to apply TMCP steel to nuclear energy areas, medium- to high-temperature regions, and ultra-high strength types such as 780 MPa and 950 MPa. Examples of the latest commercial application include surface ultra fine grain steel whose excellent brittle crack arrestability is comparable to that of high-Ni steel for cryogenic use, and ultra-thick structural steel plate that allows super-high welding heat input over 100kJ/mm.

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.

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.

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