scholarly journals Nominal stress based equal fatigue bearing capacity design of HSLA steel V-shaped butt-welded joints

2018 ◽  
Vol 221 ◽  
pp. 01009
Author(s):  
Wen Xue ◽  
Ping Wang ◽  
Zhibo Dong ◽  
Hongyuan Fang
Keyword(s):  
Bearing Capacity ◽  
Welded Joints ◽  
Design Method ◽  
Hsla Steel ◽  
Estimation Method ◽  
High Strength ◽  
Nominal Stress ◽  
Fatigue Load ◽  
Capacity Design ◽  
Fatigue Life Estimation

Based on nominal stress, this paper proposed a fatigue life estimation method of V-shaped butt welded joints. Then, the fatigue bearing capacity of the base metal under the same fatigue load was used as design goal of the V-shaped butt welded joints and an equal fatigue bearing capacity (EFBC) design method for V-shaped butt welds was thus formed. High strength low alloy steel Q690 was chosen as the experimental material to carry out the equal fatigue bearing capacity design.

scholarly journals Nominal Stress-Based Equal-Fatigue-Bearing-Capacity Design of under-matched HSLA Steel Butt-welded Joints

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 880 ◽  
Author(s):  
Xue Wen ◽  
Ping Wang ◽  
Zhibo Dong ◽  
Yong Liu ◽  
Hongyuan Fang
Keyword(s):  
Bearing Capacity ◽  
Fatigue Limit ◽  
Base Metal ◽  
Welded Joints ◽  
Design Method ◽  
Hsla Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Nominal Stress ◽  
Load Carrying

Under-matched welds could minimize the tendency of cold cracking and reduce the preheating operations when high strength steels are welded. However, its low load-carrying capacity might make the high strength parent metal meaningless. With the aim of improving the fatigue limit of under-matched butt-welded joints, this work establishes a nominal stress based fatigue design method for under-matched butt welds while considering its heterogeneous mechanical features. The fatigue life of the base metal is set to be the design goal for the under-matched butt-welded joints, which has scarce been tried before. An equal-fatigue-bearing capacity (EFBC) design method fit for the under-matched butt-welded joints is thus applied with the aims of equal fatigue limit of base metal. X-shaped butt-welded joint is selected to carry out experimental verification where HSLA steel Q550 as the base metal and ER70S-6 as the under-matched filler metal are used. The results show that the EFBC method proposed here is feasible. Note that the EFBC method is valid only in high cycle fatigue.

scholarly journals A Fracture Mechanics-Based Optimal Fatigue Design Method of Under-Matched HSLA Steel Butt-Welded Joints with Imperfections

2019 ◽  
Vol 9 (17) ◽  
pp. 3609 ◽  
Author(s):  
Wen ◽  
Wang ◽  
Dong ◽  
Fang
Keyword(s):  
Fracture Mechanics ◽  
Welded Joints ◽  
Design Method ◽  
Hsla Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Engineering Structures ◽  
Fatigue Design ◽  
Load Carrying ◽  
Practical Engineering

The trend of light-weight structures leads to the wide application of high strength steels in engineering structures. When welding high strength steels, under-matched consumables could reduce the cold-cracking tendency, simplifying the preheating process. However, under-matched welds would sometimes make the high strength base metal pointless due to its weak load-carrying capacity. For the purpose of enhancing the fatigue strength of under-matched welded joints, a fracture mechanics-based optimal fatigue design method of under-matched butt-welded joints is proposed in this work. Heterogeneous mechanical features of welded joints, which are not considered in current standards and codes, are incorporated into the optimal design method. The fatigue limit of the high strength parent metal is taken as the design target, which has seldom been reported. HSLA steel Q550, with its under-matched consumable ER70S-6 composed X-shaped butt-welds, is selected for experimental verification. The experimental results indicate that the fracture mechanic based equal-fatigue-bearing-capacity (EFBC) design method established in this work is feasible and could be a valuable reference for the design of practical engineering structures.

Correlation between GMAW Parameters and Mechanical Properties of Hot-Rolled, High-Strength Low-Alloy (HSLA) Steel Butt Joints

2021 ◽  
Vol 890 ◽  
pp. 25-32
Author(s):  
Alin Constantin Murariu ◽  
Aurel Valentin Bîrdeanu
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Hsla Steel ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Steel Plates ◽  
Experimental Program ◽  
Welding Parameters ◽  
Main Process ◽  
Hot Rolled

In all industrial fields, the product requirements are more and more demanding. HSLA steels are designed to provide higher atmospheric corrosion resistance and improved mechanical properties than structural steels. The paper presents the results of an experimental program based on factorial design, applied to predict the mechanical properties of butt-welded joints of S420MC and S460MC hot-rolled, high-strength low-alloy (HSLA) steel plates with 2mm, 4mm and 8mm thickness. Gas Metal Arc Welding (GMAW) was used and correlations between the main process parameters and the related mechanical properties of the welded joints were found. Obtained mathematical correlations can be exploited to provide optimal combination of welding parameters to fit the quality requirements of the end-users for envisaged welded product.

scholarly journals Analysis of Influence of the Welding Procedure on Impact Toughness of Welded Joints of the High-Strength Low-Alloyed Steels

2020 ◽  
Vol 10 (7) ◽  
pp. 2205 ◽  
Author(s):  
Andreja Ilić ◽  
Ivan Miletić ◽  
Ružica R. Nikolić ◽  
Vesna Marjanović ◽  
Robert Ulewicz ◽  
...  
Keyword(s):  
Impact Toughness ◽  
Welded Joints ◽  
Hsla Steel ◽  
High Strength ◽  
Inert Gas ◽  
Welding Technology ◽  
First Case ◽  
Low Alloyed Steel ◽  
Welding Procedure ◽  
The Impact

This paper presents results of comparison of two welding procedures’ influence on selected properties of the welded joints of high-strength low-alloyed steel (HSLA), specifically the impact toughness and the hardness distribution in the specific zones of “single V” butt multiple-pass welded joints. Based on results obtained from experiments, the two applied welding technologies were evaluated. They differ by the welding grove geometry and by the applied root pass welding procedure. Both procedures use MAG (Metal Active Gas) welding for execution of the filling and covering passes, while the root passes are executed by the MMA (Manual Metal Arc) procedure in the first case and by the MIG (Metal Inert Gas) procedure in the second. Experimentally obtained values of the fracture energy of the welded samples for both procedures were smaller than the values for the parent metal, which confirms the fact that welding causes degradation of the mechanical properties of HSLA steel; thus, any welding technology parameters must be so selected to mitigate this deficiency.

scholarly journals Weldability of Underwater Wet-Welded HSLA Steel: Effects of Electrode Hydrophobic Coatings

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1364
Author(s):  
Jacek Tomków
Keyword(s):  
Heat Affected Zone ◽  
Welded Joints ◽  
Hsla Steel ◽  
High Strength ◽  
Filler Material ◽  
Visual Test ◽  
Hydrophobic Coatings ◽  
Hydrophobic Substances

The paper presents the effects of waterproof coatings use to cover electrodes on the weldability of high-strength, low-alloy (HSLA) steel in water. With the aim of improving the weldability of S460N HSLA steel in water, modifications of welding filler material were chosen. The surfaces of electrodes were covered by different hydrophobic substances. The aim of the controlled thermal severity (CTS) test was to check the influence of these substances on the HSLA steel weldability in the wet welding conditions. The visual test, metallographic tests, and hardness Vickers HV10 measurements were performed during investigations. The results proved that hydrophobic coatings can reduce the hardness of welded joints in the heat-affected zone by 40–50 HV10. Additionally, the number of cold cracks can be significantly reduced by application of waterproof coatings on the filler material. The obtained results showed that electrode hydrophobic coatings can be used to improve the weldability of HSLA steel in underwater conditions.

scholarly journals Imperfections and Modelling of the Weld Bead Profile of Laser Butt Joints in HSLA Steel Thin Plate

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 151
Author(s):  
Patricio G. Riofrío ◽  
José A. M. Ferreira ◽  
Carlos A. Capela
Keyword(s):  
Laser Welding ◽  
Welded Joints ◽  
Hsla Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Weld Bead ◽  
Welding Parameters ◽  
Great Decrease ◽  
Weld Quality ◽  
Butt Joints

In many applications that use high strength steels, structural integrity depends greatly on weld quality. Imperfections and the weld bead geometry are influencing factors on mechanical properties of the welded joints but, especially in the fatigue strength, they cause a great decrease. The proper knowledge of these two factors is important from the nominal stress approach to the fracture mechanics approaches. Studies concerning the profile and imperfections of the weld bead in laser welding for thin plates of high strength steels are scarce. In this work, these two aspects are covered for five series single and double-welded joints, butt joints in a 3 mm thick HSLA steel, welded in a small range of welding parameters. The actual profiles captured with profilometer were modeled with proposed geometric parameters achieving an adequate fit with values of the coefficient of determination ℜ2 greater than 0.9000. Description of imperfections includes the distributions of porosity and undercuts. The evaluation of the weld quality, taking as guide the ISO 13919-1 standard determined B and D levels for the welded series while based on the stress-concentrating effect, showed a greater detriment in those series with undercuts and excessive penetration. The analysis of variance validated the results of the different combinations of laser welding parameters and showed, for the factorial experimental design, a more significant effect of the welding speed.

scholarly journals Fatigue Examination of HSLA Steel with Yield Strength of 960 MPa and Its Welded Joints under Strain Mode

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 228
Author(s):  
Tomasz Ślęzak
Keyword(s):  
Fatigue Life ◽  
Welded Joints ◽  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Hsla Steel ◽  
Fatigue Crack Initiation ◽  
High Strength ◽  
Fusion Line ◽  
Cycle Fatigue ◽  
Strain Mode

The full benefits of application the high strength low alloyed steels HSLA can be achieved if the structures will be able to carry the alternate loads and fatigue cracks will not be formed, even in the vicinity of welded joints. For this reason the purpose of this study is to find and to explain the influence of different factors on fatigue crack initiation and the nature of crack propagation in HSLA steel and its welded joints. The S960QL steel and two types of welded joints were subjected to low cycle fatigue (LCF) tests at a strain mode and the received surfaces of fractures were analyzed using SEM microscope. Additionally, the microhardness measurements and the residual stress analyze in a cross-section of the joint were conducted. The maximum hardness was determined on the fusion line and more favorable hardness distribution was in the square joints than in single-V. Compiled maps of residual stresses have shown that the local orientation and values of the principal stress vector near the fusion line can influence negative the fatigue life. Finally, the square joints tested in the low cycle fatigue regime have shown a slightly higher fatigue life in comparison with single-V.

Investigations of Microstructure of Resistance Spot-Welded Joints Made of HSLA340 and DP600 Steels / Badanie Mikrostruktury Złączy Zgrzewanych Punktowo Ze Stali HSLA340 I DP600

2012 ◽  
Vol 57 (4) ◽  
pp. 1081-1086 ◽  
Author(s):  
A. Ignasiak ◽  
M. Korzeniowski ◽  
A. Ambroziak
Keyword(s):  
Welded Joints ◽  
High Strength Steel ◽  
Hsla Steel ◽  
High Strength ◽  
Dual Phase ◽  
Low Carbon ◽  
Spot Welds ◽  
Bainite Microstructure ◽  
Martensite Microstructure ◽  
Carbon Martensite

The paper presents results of metallographic investigations of spot welds made of high-strength steel HSLA340 and dual-phase DP600 steel. Low-carbon martensite microstructure was found in the weld nugget of HSLA steel. The DP600 steel shows martensite and bainite microstructure. For both steels, no carbides of microadditives were found because they dissolved in liquid nugget and could not precipitate again because of rapid heat abstraction. Moreover, no transcrystallisation was found in both steels, which proves good mixing of the materials within the weld.

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