Special features of the formation of bainitic structures of granular morphology in the weld zone of welded joints in high-strength low-alloy steels

2011 ◽  
Vol 25 (2) ◽  
pp. 105-109 ◽  
Author(s):  
D.P. Cherpasov ◽  
M.N. Seidurov ◽  
A.A. Ivanaiskii
Keyword(s):  
Welded Joints ◽  
Weld Zone ◽  
High Strength ◽  
Low Alloy Steels ◽  
Alloy Steels ◽  
Granular Morphology

scholarly journals DIFFUSION OF HYDROGEN IN WELDED JOINTS OF STRUCTURAL STEELS

2017 ◽  
Vol 21 (6) ◽  
pp. 85-95 ◽  
Author(s):  
N. N. Sergeev ◽  
A. N. Sergeev ◽  
S. N. Kutepov ◽  
A. E. Gvozdev ◽  
E. V. Ageev
Keyword(s):  
Diffusion Coefficient ◽  
Weld Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Chemical Potential ◽  
Weld Zone ◽  
Base Material ◽  
High Strength ◽  
Low Alloy Steels ◽  
Alloy Steels

High-strength low-alloy steels are widely used in the construction of welded metal structures. The main advantage of these steels is good combination of strength and toughness, and weldability. However, when welding high strength low alloy steels during cooling of the weld to a temperature below 150-100 °C there may be a risk of formation of bulk crystal structures defects in the weld zone - cold cracks. It was experimentally established that one of the factors contributing to the formation of cold cracks may be the occlusion of hydrogen in the atmosphere of arc plasma in the solidifying weld metal, from which diffusion hydrogen may diffuse to different areas of the weld after cooling. Hydrogen cracking typically has a tendency to slow down i.e. cracks can occur several days after the completion of welding process. As a rule, hydrogen induced cracking occurs either in the original steel in the heat-affected zone or in the weld metal, which is important, topical and long been researched by various scientific schools. Modern technologies of high strength low alloy steels processing have significantly improved the quality of the base material by reducing the amount of carbon and impurities, which has increased the stability of weld in the heat affected zone (HAZ) to hydrogen induced cold cracking. The paper presents modern approaches to the definition of diffusion coefficient of hydrogen in welded joints of high-strength low-alloy steels. Taking into account the temperature, the gradient of chemical potential and continuity conditions there has been considered the process of mass transfer of hydrogen under the influence of diffuse inhomogeneous mediums. It has been shown that the local effects of changing pressure and chemical potential are described using the equation of generalized potential of the diffusing substance. Our paper presents analytical expressions to determine the apparent diffusion coefficient of hydrogen in different local areas of a welded joint depending on temperature.

Analysis of the Effects of Welding Conditions on the Formation of the Structure of Welded Joints of Low-Carbon Low-Alloy Steels

2020 ◽  
Vol 844 ◽  
pp. 146-154
Author(s):  
Dmytro Laukhin ◽  
Valerii Pozniakov ◽  
Oleksandr Beketov ◽  
Nataliia Rott ◽  
Anatolii Shchudro
Keyword(s):  
Welded Joints ◽  
Special Interest ◽  
Welded Joint ◽  
Weld Zone ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Influence Zone ◽  
Alloy Steels ◽  
Thermal Influence ◽  
Welding Processes

To obtain reliable joints in the conditions of open construction is complicated or impossible to use stationary machines and apparatuses, so requirements to welding processes are of special interest. The most interest concerning the support of strength and reliability of welded joint is specific processes developed after the crystallization of weld at weld zone. The value of the zone of thermal influence depends on the welding conditions and properties of metal that is welded. That is why the research on the influence of welding conditions on the formation of the structure of welded zone and thermal influence zone is actual.

scholarly journals The influence of the carbon equivalent on the weldability of high-strength low-alloy steel in the water environment

2019 ◽  
Vol 91 (5) ◽  
Author(s):  
Jacek Tomków ◽  
Michalina Tomków
Keyword(s):  
Weld Metal ◽  
Yield Point ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Water Environment ◽  
High Strength ◽  
Carbon Equivalent ◽  
Low Alloy Steels ◽  
Low Alloy Steel ◽  
Alloy Steels

From many years, the high strength low alloy steels are often used for offshore constructions. This constructions, due to the environment in which they work, require more frequent repairs than the constructions from the land. For economic reasons, repairs take place in the underwater conditions, however water significantly decreases the weldability of steel. The paper presents the results of the CTS weldability test for S460ML and S460 steels, which have a similar value of the yield point, but different carbon equivalent (CeMIS) values. The welded joints were cut into specimens, which were then subjected to Vickers HV10 hardness measurements. The experiment has shown that as the CeMIS value increases, the hardness in the heat affected zone (HAZ) of joints and in the weld metal increases.

scholarly journals Assessment the Partial Welding Influences on Fatigue Life of S700MC Steel Fillet Welds

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 334
Author(s):  
Jaromir Moravec ◽  
Jiri Sobotka ◽  
Iva Novakova ◽  
Sarka Bukovska
Keyword(s):  
Fatigue Life ◽  
Welded Joints ◽  
Welding Process ◽  
High Strength ◽  
Major Effect ◽  
Strength Properties ◽  
Low Alloy Steels ◽  
Grain Coarsening ◽  
Fine Grained ◽  
Alloy Steels

Fine-grained steels belonging to the HSLA group (High-Strength Low-Alloy steels) of steels are becoming increasingly popular and are used in both statically and dynamically stressed structures. Due to the method of their production, and thus also the method use to obtain the required mechanical properties, it is really necessary to limit the heat input values for these steels during welding. When applying temperature cycles, HSLA steels in highly heated heat-affected zones (HAZ) reveal intensive grain coarsening and also softening behaviour. This subsequently results in changes in both mechanical and brittle-fracture properties, and the fatigue life of welded joints. While grain coarsening and structure softening have a major effect on the change of strength properties and KCV (Charpy V-notch impact toughness) values of statically stressed welded joints, the effect of these changes on the fatigue life of cyclically stressed welded joints has not yet been quantified. The paper is therefore conceived so as to make it possible to assess and determine the percentage impact of individual aspects of the welding process on changes in their fatigue life. To be more specific, the partial effects of angular deformation, changes that occur in the HAZ of weld, and the notch effect due to weld geometry are assessed.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

UNIFLUX V90

Alloy Digest ◽  
1979 ◽  
Vol 28 (2) ◽  
Keyword(s):  
Carbon Dioxide ◽  
High Strength ◽  
Heat Treating ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Nickel Steel ◽  
Steel Weld Metal ◽  
Alloy Steels ◽  
Temperature Impact ◽  
Welding Electrode

Abstract UNIFLUX V90 is a continuous flux-cored welding electrode (wire) developed to weld high-strength low-alloy steels, but it may be used to weld other low-alloy steels and carbon steels. It is used to deposit typically 2.40% nickel steel weld metal with good low-temperature impact properties. Welding is protected by a shielding atmosphere of either 75% argon-25% carbon dioxide or 100% carbon dioxide. Uniflux V90 is used widely in shipbuilding and other fabricating industries. It provides around 88,000 psi tensile strength and around 26 food-pounds Charpy V-notch impact at 60 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-355. Producer or source: Unicore Inc., United Nuclear Corporation.

TRI-MARK TM-115

Alloy Digest ◽  
1983 ◽  
Vol 32 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Arc Welding ◽  
High Strength ◽  
Heat Treating ◽  
Low Alloy Steels ◽  
Mining Equipment ◽  
Alloy Steels ◽  
Temperature Impact ◽  
Welding Electrode

Abstract TRI-MARK TM-115 is a gas-shielded flux-cored welding electrode for continuous high deposition are welding. It is designed specifically for semiautomatic and automatic arc welding of high-strength low-alloy steels and quenched-and-tempered steels. This gas-sheilded tubular wire can be used for single and multiple-pass welding. It has outstanding low-temperature impact properties. Its applications including mining equipment, large vehicles and similar items. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-392. Producer or source: Tri-Mark Inc..

TRI-MARK TM-811N2

Alloy Digest ◽  
1983 ◽  
Vol 32 (4) ◽  
Keyword(s):  
Low Temperature ◽  
High Strength ◽  
Heat Treating ◽  
Low Alloy Steels ◽  
Nickel Steel ◽  
Fine Grained ◽  
Subzero Temperatures ◽  
Steel Weld Metal ◽  
Alloy Steels ◽  
Welding Electrode

Abstract TRI-MARK TM-811N2 is a flux-cored welding electrode for all position semiautomatic arc welding. It is designed to weld 2-3% nickel steels for applications requiring good toughness at subzero temperatures; in addition, it is used to weld various other high-strength low-alloy steels and various fine-grained steels with low-temperature toughness. Tri-Mark TM-811N2 is used to deposit typically 2.35% nickel steel weld metal with good low-temperature impact properties. It is used for shipbuilding, oil rigs and similar structures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-389. Producer or source: Tri-Mark Inc..

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