Fatigue Life Behaviour of Transverse Fillet Weld and Transverse Fillet on Weld of the HSLA S460G2+M Followed by HFMI/PIT

2020 ◽  
Vol 899 ◽  
pp. 126-134
Author(s):  
Dahia Andud ◽  
Salina Saidin ◽  
Yupiter H.P. Manurung

This study deals with the fatigue life assessment of the transverse fillet weld and transverse fillet weld on weld fatigue specimen of the offshore steel S460G2+M with a thickness of 10 mm. These specimens were joined using gas metal arc welding (GMAW) with ER80S-N1 filler metal of 1.0 mm in diameter and mixed gases of 80% Ar + 20% CO2 as the consumables. Upon the welding completion, some of the fatigue specimens are treated using high-frequency mechanical impact device called pneumatic impact treatment (HFMI/PIT). The treatment procedure uses 90Hz of frequency, 6 bars of pneumatic pressure and 2 mm pin radius with aims to enhance the lifespan of the specimen. These fatigue specimens are classified in as-welded and HFMI/PIT. The fatigue test was conducted to all fatigue specimens until failure using a 250KN Instron fatigue machine with a constant amplitude loading, a stress ratio of 0.1 and stress loading from 55% to 75% of the yield strength of the base material. The fatigue data were evaluated based on the International Institute of Welding (IIW) evaluation procedures. Further, the fatigue life comparison between the as-welded and HFMI/PIT of both fatigue specimens also with the FAT class recommendation of the IIW for transverse fillet weld is plotted in the S-N curve diagram. Based on the assessment, it is found that the HFMI/PIT fatigue specimens attained higher fatigue life than the as-welded of both fatigue specimens. The most significant of fatigue life improvement after the HFMI/PIT is the HFMI/PIT transverse fillet weld. These treated welds obtained 256 MPa of FAT class which is 79 % higher than FAT class recommended by the IIW for the transverse fillet weld. Besides, the multi-pass welds on the groove weld of the transverse fillet weld on welds are found to contribute to a lower fatigue life of this specimen due to the existing weld defects on the fractured surface of the groove weld.

This study deals with the fatigue life enhancement of the transverse fillet weld on welds of 10mm thickness of the high strength low alloy steel (HSLA) S460G2+M which is treated using high frequency mechanical impact tool called pneumatic impact treatment (HFMI/PIT). Initially, the plate S460g2+M is prepared with groove angles of butt joint and joined using gas metal arc welding (GMAW) with multi-pass welds followed by to weld the transverse attachment over the existing welds to produce a fillet weld on welds. Secondly, the HFMI/PIT treatment is applied on the fillet weld toe using 90Hz frequency, 6 bars of pneumatic pressure and 2 mm pin radius. Thirdly, the fatigue tests with constant amplitude loading are conducted on the untreated and treated specimens by applying 0.1 stress ratio and 55% to 75% stress loading from the yield strength of the base material. All fatigue data were evaluated based on international welding institute (IIW) commission XIII. It is found that the fatigue life of treated specimen is higher as compared with the untreated specimen. However, it is observed that an excessive heat input due to multi-pass welds has insignificant effect to the fatigue life of the untreated specimen.


2011 ◽  
Vol 383-390 ◽  
pp. 2941-2944
Author(s):  
Wei Ming Du ◽  
Fei Xue

The crane reel is generally manufactured by section welding method when the diameter is over 380mm. With the cumulative fatigue damage principle which is based on stress S-N curve, the fatigue damage of one crane reel is analyzed by finite element method, the reel weld fatigue strength and fatigue life are calculated, and the simulation results are proved to be reliable. This method provides an efficient reference for crane reel design and residual life estimation.


2021 ◽  
Vol 2130 (1) ◽  
pp. 012016
Author(s):  
K Zając ◽  
K Płatek ◽  
P Biskup ◽  
L Łatka

Abstract The study presents a data-driven framework for modelling parameters of hardfacing deposits by GMAW using neural models to estimate the influence of process parameters without the need of creating experimental samples of the material and detailed measurements. The process of GAS Metal Arc Welding (GMAW) hardfacing does sometimes create non-homogenous structures in the material not only in deposited material, but also in the heat-affected zone (HAZ) and base material. Those structures are not fully deterministic, so the modelling method should account for this unpredictable component and only learn the generic structure of the hardness of the resulting material. Artificial neural networks (ANN) were used to create a model of the process using only measured samples without any knowledge of equations governing the process. Robust learning was used to decrease the influence of outliers and noise in the measured data on the neural model performance. The proposed method relies on modification of the loss function and several of them are compared and evaluated as an attempt to construct general framework for analysing the hardness as a function of electric current and arc velocity. The proposed method can create robust models of the hardfacing layers deposition or other welding processes and predict the properties of resulting materials even for unseen parameters based on experimental data. This modelling framework is not typically used for metallurgy, and it requires further case studies to verify its generalisability.


2019 ◽  
Vol 269 ◽  
pp. 06002
Author(s):  
Salina Saidin ◽  
Dahia Andud ◽  
Yupiter H. P. Manurung ◽  
Muhd. Faiz Mat ◽  
Noridzwan Nordin ◽  
...  

This paper deals with a comprehensive investigation of fatigue life enhancement on semiautomated Gas Metal Arc Welding (GTAW) butt weld joint which is found almost everywhere in Malaysia welding structure steel sectors. The selected material in this study was high strength low alloy steel S460G2+M commonly used extremely in steel structure due to its outstanding mechanical properties. In this investigation, the method for joining the butt weld was conducted by unprofessional welder using semi-automated GMAW. At first, suitable welding parameters were identified and formulated into welding procedure specification (WPS) qualification conforming to AWS D1.1 standard. The test specimens were prepared and tested to ensure the welding quality. Further, the HFMI using Pneumatic Impact Treatment (PIT) technique were applied at the weld toe of the butt weld as tool for fatigue life enhancement. To investigate the influence of HFMI/PIT on the fatigue strength, the specimens were undergone fatigue test using universal fatigue machine using a constant amplitude loading. Finally, the comparison of the fatigue strength of as welded and treated specimens to indicate the beneficial influence of the treatment. Yes, the conduction by unprofessional welder using semi-automatic GMAW, the findings showed the improvement of fatigue strength and slope of S-N curves. In addition, the fracture location of test specimen shows physically affected by shifting from critical weld transition to base metal. The tensile test and hardness value also showed a slight difference as compared to untreated specimens.


Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1345
Author(s):  
Karsten Günther ◽  
Jean Pierre Bergmann

Vanadium carbide (VC) reinforced FeCrVC hardfacings have become important to improve the lifetime of tools suffering abrasive and impact loads. This is because the microstructural properties of such hardfacings enable the primary VCs to act as obstacles against the penetrating abrasive. Because dilution is supposed to be the key issue influencing the precipitation behaviour of primary carbides during surfacing, the development of deposit welding processes exhibiting a reduced thermal impact, and hence lower dilution to the base material, is the primary focus of the current research. By inserting an additional hot wire in the melt, an approach was developed to separate the material and energy input during gas metal arc welding (GMAW), and hence realised low dilution claddings. The carbide content could be increased, and a grain refinement was observed compared with conventional GMAW. These effects could be attributed to both the reduced dilution and heterogeneous nucleation.


Author(s):  
Jian Le ◽  
Hua Zhang ◽  
Jin-wen Li

Purpose This study aims to improve the welding quality and efficiency, and an algorithm should be designed to realize tracking space-curved fillet weld joints. Design/methodology/approach Fillet weld joints tracking based on the two wheels and the horizontal slider coordinated movement has been studied. The method of pattern recognition is used to identify the height deviation, and the analysis of the accuracy corresponding to recognizing height deviations has been researched. The proportional control algorithm is used to control the vertical and horizontal sliders movement, so fillet weld joints tracking in the height direction has been achieved. Based on wheels and vertical and horizontal sliders coordinated movement, the algorithm of space-curved fillet weld joints tracking has been researched. Findings Some experiments have been done, and experimental results show that the welding robot can track space-curved fillet weld joints with high accuracy and good reliability. Research limitations/implications The welding robot can improve the welding quality and efficiency. Practical implications The welding robot can track fillet weld joints in ship panels, and it was shown that the welding robot could track space-curved fillet weld joints with high accuracy and good reliability. Social implications The welding robot has many industrial and social applications. Originality/value There are various forms of fillet weld joints in the industry, and the fillet weld is curved in the space. Experimental results show that the welding robot can track space-curved fillet weld joints with good stability and high precision.


2015 ◽  
Vol 812 ◽  
pp. 29-34 ◽  
Author(s):  
Ádám Dobosy ◽  
János Lukács

The objective of this article is to present the first results of our research work. In order to determination and comparison of the fatigue resistance, high cycle fatigue tests (HCF) were performed on RUUKKI OPTIM S690QL quenched and tempered high strength steel. In parallel these; welded joints were made on the same steel using gas metal arc welding (GMAW, MIG/MAG) to preparation of the cyclic investigations of the welded joints. In the article, the performance of the welding experiments will be presented; along with the results of the HCF tests executed on the base material and its welded joints. Furthermore, our results will be compared with different literary data.


Author(s):  
Inge Lotsberg ◽  
Arne Fjeldstad ◽  
Morten Ro Helsem ◽  
Narve Oma

Fatigue life assessment is important for all floating offshore structures related to the new building stage but also related to lifetime extensions. Fatigue cracking occurs normally due to uncertainties in estimated fatigue life and this is a well-known problem for floaters. In this paper the aim has been to look deeper into the effects of improvement methods for improvement of the fatigue life of structural connections. Fatigue testing of full size fillet welded doubling plates has been performed of a specimen in as welded condition for comparison with two specimens improved by grinding. The paper also presents an alternative S-N curve for grinded details. The primary goal is to assess the possibility for fatigue life improvement of fillet welded doubling plates where fatigue cracking may initiate from the weld root. The information gained in this project is considered to be important for the offshore floater industry, as well as for development of new fatigue assessment procedures and requirements in standardization.


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