LJ707-Crnimo Flux Cored Wire of Basic Slag System Be Applied to Non-Preheating Welding Technology of HSLA

2013 ◽  
Vol 364 ◽  
pp. 584-588
Author(s):  
Tao Gao Hurile ◽  
Fu Rong Chen ◽  
Yong Fei Hao ◽  
Ai Ai Zhang
Keyword(s):  
Low Temperature ◽  
Welded Joints ◽  
Treatment Process ◽  
Slag System ◽  
Bending Test ◽  
Cored Wire ◽  
Microstructure Observation ◽  
Heating Treatment ◽  
Temperature Impact ◽  
The Impact

This article investigates the welded joints of HSLA Q550 without preheating and post-heating treatment process. Tensile test, bending test, low temperature impact test, and the impact fractures and joint microstructure observation and analysis are used.The test result shows that the welded joins achieves equal strength with base metal. The average values of the welded joints impact absorbed energy at-20 °C are greater than 40J and at-40 °C its average values are greater than 27J, thus the low-temperature impact energy joint can meet the service requirements of hydraulic support. It shows that choosing proper welding material, developing reasonable welding and post-heating treatment process can cancel the preheating process of Q550 steel welding.

Experimente Research of Filler-Bitumen Ratio Impact on Asphalt Mixture Performance

2013 ◽  
Vol 361-363 ◽  
pp. 1851-1856 ◽  
Author(s):  
Lin Cao
Keyword(s):  
Low Temperature ◽  
Bending Strength ◽  
Asphalt Mixture ◽  
Bending Test ◽  
Bending Strain ◽  
Cracking Performance ◽  
Beam Bending ◽  
Bending Failure ◽  
The Impact ◽  
Asphalt Mortar

AH-130 base asphalt graded according to the upper limit of AC-16 close gradation is selected in this paper to identify the impact of asphalt mortar of different filler-bitumen ratios on asphalt mixture’s road performance through small beam bending test at low temperature. And then bending failure energy, in substitute of bending strength, bending strain, is used to evaluate the anti-cracking performance of asphalt mixture at low temperature.

Effect of Heat Treatment Technique on the Low Temperature Impact Toughness of Steel EQ70 for Offshore Structure

2017 ◽  
Vol 36 (8) ◽  
pp. 825-830 ◽  
Author(s):  
Su-Fen Tao ◽  
Yun-Jin Xia ◽  
Fu-Ming Wang ◽  
Jie Li ◽  
Ding-Dong Fan
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Impact Toughness ◽  
Treatment Technique ◽  
Offshore Structure ◽  
Treatment Techniques ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness ◽  
The Impact ◽  
Quenching And Tempering

AbstractCircle quenching and tempering (CQ&T), intercritical quenching and tempering (IQ&T) and regular quenching and tempering (Q&T) were used to study the influence of heat treatment techniques on the low temperature impact toughness of steel EQ70 for offshore structure. The steels with 2.10 wt. % Ni (steel A) and 1.47 wt. % Ni (steel B) were chosen to analyze the effect of Ni content on the low temperature impact toughness of steel EQ70 for offshore structure. The fracture morphologies were examined by using a scanning electron microscope (SEM, JSM-6480LV), and microstructures etched by 4 vol. % nitric acid were observed on a type 9XB-PC optical microscope. The results show that the impact toughness of steel A is higher than that of steel B at the same test temperature and heat treatment technique. For steel B, the energy absorbed is, in descending order, CQ&T, Q&T and IQ&T, while for steel A, that is CQ&T, IQ&T and Q&T. The effects of heat treatment on the low temperature impact toughness are different for steels A and B, the absorbed energy changes more obviously for steel A. The results can be significant references for actual heat treatment techniques in steel plant.

Improvement in Toughness of Transportation and Storage Cask Steel for Spent Nuclear Fuel

2007 ◽  
Author(s):  
Hee Kyung Kwon ◽  
Byoung Koo Kim ◽  
Kuk Cheol Kim ◽  
Keun Ho Song ◽  
Jeong Tae Kim
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Radioactive Material ◽  
Low Alloy Steels ◽  
Tempering Temperature ◽  
Impact Properties ◽  
Temperature Impact ◽  
The Impact

Nuclear power plants have been operated for fifty years. Currently the managements of spent fuel are on progress vigorously. Casks for transportation and/or storage of spent nuclear fuel are usually made of SA350 low alloy steels. The wall thickness of the casks are greater than 300mm. But because leakage of nuclear fuel or radioactive material from unexpected brittle fracture is not acceptable, Nil-ductility transition temperatures of colder than −150°F are needed. The effects of chemical composition and heat treatment on low temperature impact properties of SA350 are investigated in this study. The microstructure of SA350 steel is composed of ferrite and pearlite. The variations of microstructure, low temperature impact properties and strength at room temperature with carbon, vanadium and manganese content are analyzed. To improve the low temperature impact properties, heat treatment at an temperature between quenching and tempering temperature is introduced. With the optimum combination of alloying elements and heat treatment, the impact properties can be improved down to the level of nil-ductility transition temperature −150°F.

scholarly journals Weldability of S700MC steel welded with the hybrid plasma + MAG method

2020 ◽  
Vol 7 ◽  
pp. 4 ◽  
Author(s):  
Beata Skowrońska ◽  
Tomasz Chmielewski ◽  
Dariusz Golański ◽  
Jacek Szulc
Keyword(s):  
Impact Toughness ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
High Efficiency ◽  
Bending Test ◽  
Mag Welding ◽  
High Yield ◽  
Hybrid Plasma ◽  
The Impact ◽  
Welding Processes

The paper describes the microstructure of welded joints produced by the plasma+MAG (Metal Active Gas) method of S700MC high yield strength steel (700 MPa). Welded joints of thermomechanical steel have been made with different values of heat input. The results of metallographic research of welded joints, microstructure of the weld and heat affected zone, hardness distribution and impact toughness are presented. The heat affected zone consists of two sub-zones with different grain size and lowered hardness. The tensile test show that strength of welded joints was slightly reduced and the bending test revealed no crack formation in the weld. The impact toughness of measured welded samples with V-notch in HAZ (heat affected zone) reached high values that are higher comparing to samples with notch placed in the weld area. The investigation results show that the use of plasma concentrated heat source together with MAG welding arc does not significantly change the structure and deteriorate properties of welded S700MC thermomechanically treated high strength steel. The hybrid plasma+MAG welding method has a potential to become a beneficial alternative to other welding processes due to its high efficiency, reduced amount of weld metal content or limited requirements for a preparation of edges of welded joints.

Effect of Heat Input on Toughness of Deposited Metal at -40οC of Self-Shielded Flux-Cored Wire

2011 ◽  
Vol 291-294 ◽  
pp. 979-983
Author(s):  
Shao Peng Song ◽  
Zhuo Xin Li ◽  
Guo Dong Li ◽  
Tian Li Zhang
Keyword(s):  
Low Temperature ◽  
Heat Input ◽  
Polygonal Ferrite ◽  
Granular Bainite ◽  
Chemical Compositions ◽  
Cored Wire ◽  
Slight Tendency ◽  
Deposited Metal ◽  
Low Temperature Toughness ◽  
The Impact

The effect of welding heat input ranging from 1.507 KJ/mm to 2.987KJ/mm on low temperature toughness of deposited metal made by self-shielded flux-cored wire has been investigated. The results showed that low temperature toughness decreased with the increase of heat input, and the impact fracture changed from ductile to cleavage fracture. In addition, the chemical compositions demonstrated a slight tendency to decrease with increasing heat input. While, heat input has little effect on inclusions of deposited metal. Higher heat input lead to grains coarsened further, reduced acicular ferrite and granular bainite, and increased polygonal ferrite, which mainly lead to toughness decreased.

The Impact of LPG Storage Tank Steel Specimen Fracture Analysis of Welded Joints

2011 ◽  
Vol 295-297 ◽  
pp. 1890-1895
Author(s):  
Wei Gu ◽  
Guo Ping Wang ◽  
Xiao Ping Wang
Keyword(s):  
Low Temperature ◽  
Welded Joints ◽  
Storage Tank ◽  
Welding Process ◽  
Steel Specimen ◽  
Low Temperature Storage ◽  
Steel Making ◽  
The Impact ◽  
Temperature Storage ◽  
Fracture Specimens

Take series of impact tests on welded joints for steel 09MnNiDR of LPG tank manufacture. And take scanning electron microscopy on impact fracture specimens. The results for the LPG storage tanks at low temperature welding process of steel making and the structure of low temperature storage tank to provide data to support safety analysis.

scholarly journals Microstructural and Mechanical Characterization of Electron Beam Welded Joints of High Strength S960QL and Weldox 1300 Steel Grades

2017 ◽  
Vol 62 (2) ◽  
pp. 627-634 ◽  
Author(s):  
S. Błacha ◽  
M.S. Węglowski ◽  
S. Dymek ◽  
M. Kopyściański
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Welded Joints ◽  
Base Material ◽  
Steel Grade ◽  
Fusion Line ◽  
Bending Test ◽  
Metallographic Examination ◽  
Steel Grades ◽  
The Impact

Abstract The paper shows the results of metallographic examination and mechanical properties of electron beam welded joints of quenched and tempered S960QL and Weldox 1300 steel grades. The aim of this study was to examine the feasibility of producing good quality electron beam welded joints without filler material. Metallographic examination revealed that the concentrated electron beam significantly affects the changes of microstructure in the weld and the adjacent heat affected zone (HAZ) in both steel grades. The microstructure of the welded joints is not homogeneous. The four zones, depending on the distance from the weld face, can be distinguished. Basically, the microstructure of the weld consists of a mixture of martensite and bainite. However, the microstructure of HAZ depends on the distance from the fusion line. It is composed of martensite near the fusion line and a mixture of bainite and ferrite in the vicinity of the base material. Significant differences in mechanical properties of the welded joints were observed. For a butt welded joint of the S960QL steel grade the strength is at the level of the strength of the base material (Rm = 1074 MPa). During the bending test the required angle of 180° was achieved. The impact strength at −40°C was 71,7 J/cm2. In the case of the Weldox 1300 steel grade butt welded joints exhibit high mechanical properties (Rm = 1470 MPa), however, the plastic properties are on the lower level than for the base material.

Microstructure and Impact Toughness of Flux-Cored Arc Welded SM570-TMC Steel at Low and High Heat Input

2020 ◽  
Vol 991 ◽  
pp. 3-9
Author(s):  
Herry Oktadinata ◽  
Winarto Winarto ◽  
Eddy S. Siradj
Keyword(s):  
Low Temperature ◽  
Impact Toughness ◽  
Base Metal ◽  
Heat Input ◽  
Charpy Impact ◽  
Cored Wire ◽  
Average Heat ◽  
Weld Metals ◽  
Flux Cored Arc Welding ◽  
The Impact

This work investigated microstructure and impact toughness of multi-pass flux-cored arc welded SM570-TMC steel. A comparison was made between weldments fabricated with average heat input of 0.9 kJ/mm and 1.4 kJ/mm, respectively. SM570 steel plate with 16 mm nominal thickness and 1.2 mm diameter of E81-Ni1 flux-cored wire were selected in this experiment. Multi-pass flux-cored arc welding (FCAW) was performed using carbon dioxide shielding gas. Then the weldments were observed using optical microscopy, scanning electron microscope (SEM) and electron probe micro analyzer (EPMA). The steel joint strength was measured via tensile test, and Charpy impact test was performed at three different test temperatures. The microstructure observation exhibited the base metal mainly consist of ferrite and pearlite features, while the weld metal contained the acicular ferrites, polygonal ferrites and M-A constituent at both different heat inputs. The impact toughness of base metal is superior than weld metals. The weld metals fabricated at average heat input of 0.9 kJ/mm have a higher low temperature impact toughness than using heat input of 1.4 kJ/mm. The acicular ferrites amount that significant reduced at the higher heat input may degrade the toughness at low temperature.

TEM comparison of osmium vs osmium with potassium ferricyanide secondary fixatives and the impact of secondary fixative temperature on tissue preservation/contrast quality

1996 ◽  
Vol 54 ◽  
pp. 910-911
Author(s):  
J. W. Horn ◽  
B. J. Dovey-Hartman ◽  
V. P. Meador
Keyword(s):  
Osmium Tetroxide ◽  
Potassium Ferricyanide ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Cacodylate Buffer ◽  
Transmission Electron Microscopic ◽  
Glutaraldehyde Solution ◽  
Temperature Impact ◽  
The Impact

Osmium tetroxide (OsO4) is a universally used secondary fixative for routine transmission electron microscopic evaluation of biological specimens. Use of OsO4 results in good ultrastructural preservation and electron density but several factors, such as concentration, length of exposure, and temperature, impact overall results. Potassium ferricyanide, an additive used primarily in combination with OsO4, has mainly been used to enhance the contrast of lipids, glycogen, cell membranes, and membranous organelles. The purpose of this project was to compare the secondary fixative solutions, OsO4 vs. OsO4 with potassium ferricyanide, and secondary fixative temperature for determining which combination gives optimal ultrastructural fixation and enhanced organelle staining/contrast.Fresh rat liver samples were diced to ∼1 mm3 blocks, placed into porous processing capsules/baskets, preserved in buffered 2% formaldehyde/2.5% glutaraldehyde solution, and rinsed with 0.12 M cacodylate buffer (pH 7.2). Tissue processing capsules were separated (3 capsules/secondary fixative.solution) and secondarily fixed (table) for 90 minutes. Tissues were buffer rinsed, dehydrated with ascending concentrations of ethanol solutions, infiltrated, and embedded in epoxy resin.

Sign in / Sign up

Export Citation Format

Share Document