scholarly journals Very Low Cyclic Fatigue Properties of Butt Welded Joints Containing Weld Defects. Study of Acceptable size of defects in girth welds of gas pipelines.

1999 ◽  
Vol 17 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Atsushi SETO ◽  
Tomoki MASUDA ◽  
Susumu MACHIDA ◽  
Chitoshi MIKI
Keyword(s):  
Welded Joints ◽  
Cyclic Fatigue ◽  
Fatigue Properties ◽  
Gas Pipelines ◽  
Weld Defects ◽  
Girth Welds

INVESTIGATION OF TRANSVERSE CRACKS IN ANNULAR WELDED JOINTS OF MAIN GAS PIPELINES LINEAR PART

2021 ◽  
pp. 34-41
Author(s):  
V. A. Zaznobin ◽  
A. V. Nekrasov ◽  
A. V. Pankratov
Keyword(s):  
Welded Joints ◽  
Linear Part ◽  
Correct Identification ◽  
Gas Pipelines ◽  
Destructive Testing ◽  
Transverse Cracks ◽  
Additional Control ◽  
Non Destructive

Statistics of accidents and incidents on main gas pipelines in recent years indicate that almost half of the technogenic events occur due to depressurization in the area of annular welded joints, mainly joints containing defects made during construction and installation work during the construction of gas pipelines. The assessment of the degree of danger and the timing of external inspection and repair or replacement of defective annular welded joints largely depends on the quality of non-destructive testing, the correct identification of the types of defects and the objective determination of their geometric dimensions. To increase the reliability of the assessment of the degree of danger of the detected defects, it is necessary to use additional control methods, in particular, destructive ones. The paper presents the results of surveys and tests of metal fragments of annular welded joints of main gas pipelines containing transverse cracks of annular welded joints in order to determine the causes of the formation of these defects and to assess the degree of danger of the detected transverse cracks of the installation welds of main gas pipelines.

Effect of Vibration on Microstructure and Fatigue Properties of 6082 CMT-Welded Joints

2021 ◽  
Author(s):  
Pengfei Zheng ◽  
Qinghua Lu ◽  
Peilei Zhang ◽  
Hua Yan ◽  
Jian Zhao ◽  
...  
Keyword(s):  
Welded Joints ◽  
Fatigue Properties

Fatigue Properties of Welded Joints of High-Carbon Steels

2007 ◽  
pp. 47-54
Author(s):  
Attila Magasdi ◽  
János Dobránszky ◽  
F. Tusz ◽  
János Ginsztler
Keyword(s):  
Welded Joints ◽  
Carbon Steels ◽  
Fatigue Properties ◽  
High Carbon

scholarly journals Fatigue Life Improvement of the High Strength Steel Welded Joints by Ultrasonic Impact Peening

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 619 ◽  
Author(s):  
Ján Lago ◽  
Libor Trško ◽  
Michal Jambor ◽  
František Nový ◽  
Otakar Bokůvka ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Welded Joints ◽  
Compressive Residual Stress ◽  
High Strength ◽  
Fatigue Properties ◽  
Low Alloy Steel ◽  
Residual Stress Field ◽  
Near Surface ◽  
Life Improvement

Ultrasonic impact peening was applied on welded joints manufactured from Strenx 700 MC high strength low alloy steel with the aim to improve the fatigue properties. Three different surface treatment parameters were tested, which resulted in transformation of the near-surface tensile residual stresses in the weld metal and heat affected zone to compressive residual stress field, while maximal values from −400 MPa up to −800 MPa were reached. The highest fatigue life improvement was reached by the double peening with the 85 N contact force, where the fatigue limit for N = 108 cycles increased from 370 MPa to 410 MPa.

Microstructures and Mechanical Properties of Welded Joints of Several High Tensile Strength Steel

2018 ◽  
Vol 941 ◽  
pp. 224-229
Author(s):  
Takahiro Izumi ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Hiroaki Miyanaga
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weld Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Steel Plates ◽  
Fatigue Properties ◽  
High Tensile Strength ◽  
The Matrix ◽  
Microstructures And Mechanical Properties

Microstructures and mechanical properties of lap fillet welded joints of several high and ultra-high tensile strength steel by arc welding were investigated. Steel plates having tensile strength of 400 (SPH400W), 590 (SPC590Y, SPC590R), 980 (SPC980Y) and 1500 MPa (SAC1500HP) class with 2 mm thickness were prepared. Four types of joints were formed by MAG welding; SPH400W/SPH400W, SPC590Y/SPC590Y, SPC980Y/SPC980Y and SAC1500HP/SPC590R. In joints with SPC590Y, SPC980Y and SAC1500HP steel which matrixes are martensitic microstructures, the HAZ softens due to transformation of martensite into ferrite with precipitating cementite. By using high and ultra-high tensile strength steel, the weld metal is strengthened due to dilution of the matrix into the weld metal and thus tensile shear strength of the welded joint increases. In the fatigue test, similar S-N diagrams were obtained in the all welded joints investigated. It seems that the effect of stress concentration due to the shape of the welded joint on fatigue properties is larger than that of the strength of the matrix.

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