Research about the Effect of Ultrasonic Impact on the Fatigue Life of Butt Weld Joint of 16MnR Steel

2011 ◽  
Vol 189-193 ◽  
pp. 3296-3299
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Huang Huang Yu ◽  
Jian Ping Shi
Keyword(s):  
Fatigue Life ◽  
Welded Joint ◽  
Butt Joint ◽  
Impact Machine ◽  
Ultrasonic Impact Treatment ◽  
Butt Weld ◽  
Impact Time ◽  
Weld Toe ◽  
The Impact ◽  
Fatigue Experiment

Surface treatment was carried out on the butt joint weldment of 16MnR steel by using the HJ-II-type ultrasonic impact machine. The ultrasonic impact current is 1.2A, the impact amplitude is 30 microns and ultrasonic impacting time is 30min and 60 min,respectively. Fatigue experiment was carried out for both treated specimen and un-treated specimen. The fatigue fracture observed with the scanning electron microscope of 6360LA type. The experimental results show that the fatigue life of the butt joint weldment of 16MnR steel can be significantly improved through the ultrasonic impact treatment. The main reason is that the ultrasonic impact can reduces the stress concentration in the weld toe, decrease the tensile stress, and even change to compressive stress in the weldment, the grain size in the welded joint can be refined. The longer the impact time, the greater increasing range of fatigue life will be. Compared to the sample without treatment, its fatigue life was increased 375.22%, 521.24%, respectively, when the impact time was 30, 60min, respectively.

Research about the Effect of Ultrasonic Impact on the Mechanical Property of Welded Butt Joint of P355NL1 Steel

2014 ◽  
Vol 644-650 ◽  
pp. 4752-4755
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Zhi Jun Zhang ◽  
Jian Ping Shi
Keyword(s):  
Mechanical Property ◽  
Residual Stress ◽  
Compressive Residual Stress ◽  
Welded Joint ◽  
Butt Joint ◽  
Impact Machine ◽  
Ultrasonic Impact Treatment ◽  
Weld Toe ◽  
The Impact ◽  
Scanning Electron

Surface treatment was carried out on the butt joint weldment of P355NL1 steel by using the HJ-II-type ultrasonic impact machine. The ultrasonic impact current is 1.5A, the impact amplitude is 20 microns and ultrasonic impacting time is 5min. Tensile test was carried out for both treated specimen and un-treated specimen. The fracture observed with the scanning electron microscope of 6360LA type. The experimental results show that although the compressive residual stress can be obtained in the surface of weld toe area, and the grain size in the welded joint can be refined, but the mechanical property of the butt joint of P355NL1 steel can not be improved through the ultrasonic impact treatment. The main reason is that the ultrasonic impact layer is only 120um, it is to thin to compared to the thickness of the specimen.

Research about the Effect of Residual Stress on the Fatigue Life of Cruciform Joint of 16MnR Steel

2011 ◽  
Vol 382 ◽  
pp. 400-403 ◽  
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Huang Huang Yu ◽  
Jian Ping Shi
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Fatigue Life ◽  
Impact Machine ◽  
Ultrasonic Impact Treatment ◽  
Heat Treated ◽  
Impact Specimen ◽  
Weld Toe ◽  
The Impact ◽  
Cruciform Joint

Surface treatment was carried out on the cruciform joint of 16MnR steel by using the HJ-II-type ultrasonic impact machine. The impact current is 1.2A, impact amplitude is 30 microns. Fatigue experiments were carried out for impact treated specimen, impact treated and heattreated specimen and un-heattreated specimen. The effect of ultrasonic impact on the hardness of the weldment and weld toe was researched. The experimental results show that the fatigue life of the cruciform joint of 16MnR steel can be significantly improved through the ultrasonic impact treatment and the hardness of weld toe can also be promoted. Compared to the sample without impact treatment, its fatigue life was increased 692.52%. The hardness of weld toe was increased 31%. Compared to the sample with heat treatment, the fatigue life of impact specimen was increased 316.67%. Compared to the sample without impact treatment, the fatigue life of impact and heat treated specimen was increased 218.69%.

Research about the Effect of Ultrasonic Impact on the Mechanical Property of Welded Cruciform Joint of P355NL1 Steel

2014 ◽  
Vol 644-650 ◽  
pp. 4748-4751
Author(s):  
Bo Lin He ◽  
Ying Xia Yu ◽  
Si Yong Lei ◽  
Jian Ping Shi
Keyword(s):  
Mechanical Property ◽  
Residual Stress ◽  
Grain Size ◽  
Compressive Residual Stress ◽  
Impact Machine ◽  
Ultrasonic Impact Treatment ◽  
Weld Toe ◽  
The Impact ◽  
Cruciform Joint ◽  
Scanning Electron

Surface treatment was carried out on the welded cruciform joint of P355NL1 steel by using the HJ-II-type ultrasonic impact machine. The ultrasonic impact current is 1.5A, the impact amplitude is 20 microns and ultrasonic impacting time is 5min. Tensile test was carried out for both treated specimen and un-treated specimen. The fracture observed with the scanning electron microscope of 6360LA type. The experimental results show that although the compressive residual stress can be obtained in the surface of weld toe area, and the grain size in the surface of welded cruciform joint can be refined, but the mechanical property of the welded cruciform joint of P355NL1 steel can not be improved through the ultrasonic impact treatment. The main reason is that the ultrasonic impact layer is only 70um, it is to thin to compared to the thickness of the specimen.

Effect of ultrasonic impact treatment on surface microstructure and fatigue properties of 6082 aluminum alloy butt joint

2018 ◽  
Vol 32 (21) ◽  
pp. 1850239 ◽  
Author(s):  
Bolin He ◽  
Yaming Feng ◽  
Li Li ◽  
Zhaoxia Chen
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Crack Initiation ◽  
Welded Joint ◽  
Butt Joint ◽  
Fatigue Properties ◽  
Ultrasonic Impact Treatment ◽  
Transmission Electron ◽  
Weld Toe ◽  
6082 Aluminum Alloy

Effect of ultrasonic impact treatment (UIT) on microstructure and fatigue properties of the aluminum alloy 6082 was studied at room temperature. The change of microstructure on the surface and the grain size after impact treatment was observed by metallographic microscope and transmission electron microscopy, respectively. The residual stress was measured by residual stress tester. The experimental results show that the UIT can lead to obvious plastic deformation layer in the treated surface, and nanocrystals were formed. Compressive residual stress of 50.4 MPa was maximum at the surface after the UIT. With an impact current of 1.0 A and impact time of 2 min, compared with untreated specimens, the fatigue strength of the 6082 aluminum alloy joint increases by about 11.18%. The fracture position for the treated specimen has been changed, the crack initiation is seen in the weld toe surface for the as-welded joint, and the crack initiation in the sub-surface for the treated specimen is comparable to the as-welded joint fatigue.

Effect of Ultrasonic Impact Treatment on Corrosion Resistance of Welded Joints of 16MnR Steel

2013 ◽  
Vol 815 ◽  
pp. 689-694 ◽  
Author(s):  
Bo Lin He ◽  
Ying Xia Yu ◽  
Jing Liu ◽  
Jian Ping Shi
Keyword(s):  
Aqueous Solution ◽  
Plastic Deformation ◽  
Corrosion Resistance ◽  
Weld Seam ◽  
Welded Joint ◽  
Residual Tensile Stress ◽  
Ultrasonic Impact Treatment ◽  
Weld Toe ◽  
The Impact ◽  
Deformation Layer

The weld seam and weld toe surface were treated by ultrasonic impact method. The contrast corrosion tests were performed in 3.5% NaCl aqueous solution both for the un-treated and treated joint. The experimental results indicate that the severe plastic deformation on the surface of weld seam and weld toe were formed by ultrasonic impact for different time, the maximum depth of the plastic deformation layer is about 300μm. Residual tensile stress in the surface of weld seam and weld toe can be changed to residual compressive stress by impact treatment, and the grain in the surface of welded joint could be refined. Compared to the un-treated joint, when the impact current is 1.2A and 1.5A, respectively, the corrosion rate of treated joint was reduced by 22.67%, 54.59%, 43.99% and 33.92%, 56.54%, 49.29%, respectively for 10, 20 and 30 min. treating. The corrosion resistance of welded joint has a certain relationship with the residual stress on the surface of welded joint. The ultrasonic impact treatment has distinct effect on the corrosion resistance of 16MnR welded joint.

scholarly journals Numerical investigation of the cope hole shape impact on fatigue life of welded joints in steel bridges

2019 ◽  
Vol 252 ◽  
pp. 07008
Author(s):  
Krzysztof Śledziewski
Keyword(s):  
Fatigue Life ◽  
Welded Joints ◽  
Hot Spot ◽  
Experimental Studies ◽  
Free Access ◽  
Steel Bridge ◽  
High Concentration ◽  
Hole Shape ◽  
Weld Toe ◽  
The Impact

Holes in the bridge girders are usually made at the joint of strips. In most cases, they are made when there is a need to make double-sided butt welds and in order to avoid welds crossing. Size of the hole is selected in order to allow full penetration of the strips across their whole width and also to ensure free access to the welds during NDT. Welded joints with holes, due to low fatigue life, are critical elements affecting durability of large-span steel bridge structures. Low fatigue life of joints with holes results mostly from high concentration of stresses near the weld toe caused by local reduction of cross-section. The paper covers parametric studies based on finite elements method in order to determine the impact of geometrical changes of the hole shape on distribution of stresses within probable areas of cracks initiation and durability of such joint. With reference to experimental studies results, four different holes geometries were analysed: semi-circle (conventional), triangle, parabola of second degree and oval. Assessment of the fatigue was performed using the so-called hot spot method, i.e. geometrical stresses. Results of the studies show that geometrical change of the hole shape affects the stresses concentration change, but it does not translate to the increase of fatigue life of such joint.

Fatigue Analysis of Small Bore Copper Nickel Full Encirclement Sleeve and Socket Welds Under Pressure Cycling

2017 ◽  
Author(s):  
Michael Jones ◽  
James Wilson ◽  
Alex Harris
Keyword(s):  
Fatigue Life ◽  
Nuclear Power ◽  
Structural Integrity ◽  
Destructive Testing ◽  
Butt Weld ◽  
Pressure Cycling ◽  
Lack Of Fusion ◽  
Copper Nickel ◽  
Process Plants ◽  
The Impact

Sleeve and socket welds are often used in small bore nuclear power plant pipework where access is too limited to allow a conventional butt-weld. These welds are also used in process plants and pipelines as a permanent repair to reinforce areas such as cracks and corrosion that might threaten the structural integrity of the component. The fillet weld associated with this type of joint is particularly susceptible to lack of fusion defects which can be problematic to detect using conventional volumetric inspection techniques. The stress concentration associated with this type of defect will impact the fatigue life and pressure retaining ability of the joint. This paper provides examples of Copper/Nickel (CuNi) sleeve weld defects and presents an approach for determining the fatigue life of socket welds due to pressure cycling within a Pressurised Water Reactor (PWR) environment. This approach is based on modelling lack of fusion features using a database of sleeve and socket weld Non-Destructive Testing (NDT) records and calculating the stress range in the remaining ligament using textbook calculations. Sensitivity studies presented herein show the impact of lack of fusion and pipe size/thickness on fatigue life.

scholarly journals Theoretical Analysis and Experimental Verification of the Influence of Geometrical Parameters on the Fatigue Life of SMA490BW Welded Butt Joint

2020 ◽  
Author(s):  
Bolin He ◽  
Yongxiang Wang ◽  
Yingxia Yu ◽  
Yuxin Zhang ◽  
Kang Wei
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Test ◽  
Butt Joint ◽  
Geometrical Parameters ◽  
Test Machine ◽  
Joint Stress ◽  
Weld Toe ◽  
Ultrasonic Fatigue ◽  
Ultra High Cycle Fatigue

Finite element mode was carried out for ultra-high cycle fatigue specimens of SMA490BW steel butt joints used in bogies. Finite element software ABAQUS/ FE-Safe was used to calculate the influences of different arc transition radius r and weld toe angles θ on joint stress concentration factor Kt and joint fatigue life N. The results show that r and θ have significant influence on the Kt and fatigue life of the SMA490BW steel butt joint for bogie. For the same inclination angle θ, Kt decreases gradually with r increasing. With θ increases, the effect of r on Kt is increasing continuously, also the effect of change in Kt caused by r on fatigue life N is increasing continuously. While in the case of same weld edge r, Kt increases with θ increasing. With r increases, the effect of θ on Kt is decreasing constantly, the effect of change in Kt caused by θ on fatigue life N is decreasing constantly. The fatigue performance of SMA490BW steel butt joint was tested by ultrasonic fatigue test machine. The results between the fatigue test and calculation is less than 15%. The finite element calculation result has important significance for improving the fatigue life of welded butt joint for bogie.

Effect of Weld Toe Burr Grinding on Fatigue Strength of Transverse Welded Specimens Made From DH36 Steel

2009 ◽  
Author(s):  
Helena Polezhayeva ◽  
Joong-Kyoo Kang ◽  
Joo-Ho Heo ◽  
Kwang-Seok Kim
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
High Cycle Fatigue ◽  
Welded Joint ◽  
Cycle Fatigue ◽  
Constant Amplitude ◽  
Joint Project ◽  
Improvement Factor ◽  
Weld Toe ◽  
Marine Engineering

The effect of weld toe grinding on fatigue life of welded joint has been studied by a number of investigators who have established that improvement factor on fatigue life is greater for higher tensile steels as compared with mild steels [1]. To establish the effect of weld toe grinding on the fatigue strength of joints made from DH36 steel, transverse welded specimens were tested under constant amplitude loading. This work was carried out by DAEWOO Shipbuilding and Marine Engineering Co. within Lloyds Register/DSME Joint Project. It was shown that the improvement factor on fatigue strength due to weld toe burr grinding for DH36 steel is above 1.5 for high cycle fatigue range.

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