scholarly journals Numerical-experimental analysis of a modified G-BOP test to evaluate cracks in weld beads in thin sheets

2021 ◽  
Author(s):  
Saulo Moretti Araújo Duarte ◽  
Heitor Silva Pereira Abdias ◽  
José Hilton Ferreira da Silva ◽  
Kelly Cristiane Gomes
Keyword(s):  
Base Metal ◽  
Thick Plate ◽  
High Strength ◽  
The Finite Element Method ◽  
Support Tool ◽  
Weld Metals ◽  
Hsla Steels ◽  
Hydrogen Induced Cracking ◽  
Critical Problems ◽  
The Relationship

Abstract One of the most critical problems related to welding is the occurrence of Hydrogen-Induced Cracking (HIC), and despite all the efforts made to mitigate this defect, it remains present in modern welding industry. Although the Gapped Bead-on-Plate (G-BOP) test is one of the most practical methods for assessing susceptibility to HIC, its application is restricted by the fact that it employs a thick plate as the base metal. Considering that many materials, such as the High-Strength-Low-Alloy (HSLA) steels, are difficult to find commercially in the required thickness, and also the fundamental need to appropriately represent the relationship between base and weld metals, da Silva, Fals and Trevisan \cite{RefG} developed a modified G-BOP test that uses a thinner sheet as the base metal. Thus, the present paper aims to evaluate the ability of the Finite Element Method (FEM) to represent the thermomechanical aspects of the G-BOP test, and then to analyze the modified version proposed by \cite{RefG} using a numerical-experimental approach with the FEM as a support tool in the investigation of HIC phenomena. The results, in addition to consolidating the modified version of the test, corroborate the FEM as an important ally in HIC studies.

Measured Imperfections and Their Effects on Strength of Component Plates of a Prototype Double Hull Structure

1995 ◽  
Vol 11 (01) ◽  
pp. 47-52
Author(s):  
Alan AhKum Pang ◽  
Robert Tiberi ◽  
Le-Wu Lu ◽  
James Ricles ◽  
Robert Dexter
Keyword(s):  
Residual Stresses ◽  
High Strength ◽  
The Finite Element Method ◽  
Initial Imperfections ◽  
Hsla Steels ◽  
Hull Structure ◽  
Surface Combatant ◽  
Double Hull ◽  
The U.S ◽  
Compressive Tests

The U.S. Navy is currently studying the use of double hull designs in high strength low alloy (HSLA) steels for surface combatant ships. A full-scale prototype double hull module was fabricated, from which multicellular box column specimens were cut for compressive tests to failure. Initial imperfections, i.e., initial plate deflections and welding residual stresses, affect the stiffness and strength of welded members. This paper describes the measurement of these imperfections and the analysis of their effects on the component plates of the cellular box specimens. Initial deflections were measured in the laboratory, where the maximum values did not exceed the Navy's guidelines or proposed values of several researchers. Residual stresses in a box specimen were also measured in the laboratory under more controlled conditions. Using the measured imperfections, the plate arrangements were analyzed using the finite element method. The imperfections were found to reduce the stiffness and strength of the plates. The results show that for accurate prediction of the strength of welded plates, initial imperfections must be taken into account.

scholarly journals NIOBIUM EFFECT ON BASE METAL AND HEAT AFFECTED ZONE MICROSTRUCTURE OF GIRTH WELDED JOINTS

2017 ◽  
Vol 23 (1) ◽  
pp. 55 ◽  
Author(s):  
Andrea Di Schino ◽  
Paolo Emilio Di Nunzio
Keyword(s):  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
High Strength ◽  
Industrial Scale ◽  
Niobium Content ◽  
Hsla Steels ◽  
Zone Microstructure

<p>The development of steels for line pipes during the last decades has been driven by the need to obtain improved combinations of high strength, toughness, weldability on industrial scale at affordable prices. The effect of niobium content on the heat affected zone (HAZ) microstructure is reported in this paper. Niobium, for its specific thermodynamic and kinetic attitude to form carbide and nitride precipitates, played a key role in the development of modern HSLA steels Results show that niobium addition is able to refine both the bainitic packet and cells size in the heat affected zone during welding. This implies that niobium  addition leads to an improvement of both toughness and hardness of welded joints manufactured by Nb micro-alloyed steels.</p><p> </p>

Integrated Experimental Procedures Assessing Hydrogen Induced Cracking Susceptibility

2015 ◽  
Author(s):  
Ahmed Fotouh ◽  
R. El-Hebeary ◽  
M. El-Shennawy ◽  
David Tulloch ◽  
Jason Davio ◽  
...  
Keyword(s):  
Base Metal ◽  
Hydrogen Content ◽  
Hsla Steel ◽  
High Strength ◽  
Carbon Equivalent ◽  
Mapping Technique ◽  
Static Fatigue ◽  
Diffusible Hydrogen ◽  
Hydrogen Induced Cracking ◽  
Implant Test

This study proposes a complete set of integrated experimental procedures to assess the risk of Hydrogen Induced Cracking (HIC) using implant test. The proposed experimental procedures assess HIC susceptibility in base metals using two measures: the implant static fatigue limit stress (σimp); and Heat Affected Zone (HAZ) maximum hardness (HV10MAX). The base metal susceptibility to HIC was evaluated by examining the effect of three welding factors: the critical cooling time between 800 °C and 500 °C (t800/500); the base metal carbon equivalent (CE); and the diffusible Hydrogen content (H). A 3-D mapping technique was used to demonstrate the interactive integrated relationships among the three examined welding factors (i.e. t800/500, CE and H) and the susceptibility of the base metal to HIC. Using the 2-D projection of the developed 3-D mapping, it was proven that the diffusible hydrogen content (H) had more effect on the HIC susceptibility of High Strength Low Alloy (HSLA) steel compared to the effect of H on the HIC susceptibility of Carbon-Manganese (C-Mn) steel.

S-Type Cultivator Tines Which Comply With ISO Standard: FEM Analysis of Stresses and Manufacturing Issues

2009 ◽  
Author(s):  
Milan Rakita ◽  
Damir Kakas ◽  
Branko Skoric ◽  
Mileta Tomovic ◽  
Qingyou Han ◽  
...  
Keyword(s):  
Fatigue Test ◽  
Fem Analysis ◽  
High Strength ◽  
Metal Working ◽  
The Finite Element Method ◽  
Iso Standard ◽  
Software Packages ◽  
Hsla Steels ◽  
Soil Preparation ◽  
Strict Requirement

ISO Standard is propagating in all aspects of industries worldwide. In order to keep competitiveness, companies are subjected to necessity for their production to be in accordance with ISO. S-type cultivator tines are used in agriculture for the soil preparation. Dimensions and the methods of testing S-tines are proposed by the standards ISO 5678-1993(E) and ISO 8947-1993(E), respectively. The fatigue test defined by ISO-8947(E) proved to be very rigorous. Stresses which develop in the S-type tine during the fatigue test were determined by the finite element method, using MSC Patran/MD Nastran software packages. Results show that tensile stresses during the test are as high as 1100 MPa (around 160 ksi). It is very strict requirement to have the yield strength higher than that value. This requirement is possible to achieve using thermomechanical treatment, a combination of metal working and heat treatment of mainly high-strength low-alloy (HSLA) steels.

Composite Solutions for Deck Catamarans

2018 ◽  
Vol 55 (1) ◽  
pp. 1-4
Author(s):  
Elena Felicia Beznea ◽  
Ionel Chirica ◽  
Adrian Presura ◽  
Ionel Iacob
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sandwich Structure ◽  
High Strength ◽  
Total Weight ◽  
External Loading ◽  
Strength Analysis ◽  
Allowable Stress ◽  
The Finite Element Method ◽  
Inland Navigation

The paper is treating the strength analysis of the main deck structure of an inland navigation catamaran for 30 passengers. The main deck should have high stiffness and high strength to resist to external loading and endure high stresses from combined bending and torsion loads. Different materials for sandwich structure of the deck have been analysed by using the Finite Element Method in order to determine the solution which accomplish better designing criteria regarding allowable stress and deformations and total weight.

Recent Observation of Hydrogen-Induced Cracking of High-Strength Steels

2008 ◽  
Author(s):  
Jr, C J McMahon ◽  
Xinyu Liu ◽  
Jun Kameda ◽  
Michael J Morgan
Keyword(s):  
Recent Observation ◽  
High Strength Steels ◽  
High Strength ◽  
Hydrogen Induced Cracking

Effect of nanosized NbC precipitates on hydrogen-induced cracking of high-strength low-alloy steel

2021 ◽  
Vol 28 (2) ◽  
pp. 249-256 ◽  
Author(s):  
En-dian Fan ◽  
Shi-qi Zhang ◽  
Dong-han Xie ◽  
Qi-yue Zhao ◽  
Xiao-gang Li ◽  
...  
Keyword(s):  
Alloy Steel ◽  
High Strength ◽  
Low Alloy Steel ◽  
Hydrogen Induced Cracking

Development of NbTiB Microalloyed HSLA Steels for High-Strength Heavy Plate

2005 ◽  
Vol 500-501 ◽  
pp. 565-572 ◽  
Author(s):  
H. Meuser ◽  
F. Grimpe ◽  
S. Meimeth ◽  
C.J. Heckmann ◽  
C. Träger
Keyword(s):  
High Strength ◽  
Optimum Process ◽  
Low Carbon ◽  
Low Alloy Steel ◽  
Alloying Element ◽  
Heavy Plate ◽  
Hsla Steels ◽  
Bainitic Microstructure ◽  
Bainitic Structure ◽  
Low Temperature Toughness

This paper deals with the development of low carbon NbTiB micro-alloyed high strength low alloy steel for heavy plates with high wall thickness. In the production of heavy plate it is remarkably difficult to achieve a combination of high strength and good low-temperature toughness. Bainitic microstructures have shown the capability to attain such requirements. To achieve a bainitic microstructure even for heavy wall products the formation of bainite can be promoted and supported by the use of small amounts of boron as a micro-alloying element. This industrial research project is based on the addition of small amounts of boron to promote the desired bainitic structure. Mill rolling trials were carried out to determine the optimum process parameters. The results of experimental mill rolling trials on 35 mm plates will be presented in this paper.

Sign in / Sign up

Export Citation Format

Share Document