Effects of temperature on the local fracture toughness behavior of Chinese SA508-III welded joint

It is important for the design engineer to realize that scatter and variability of materials properties are inevitable and must be dealt with appropriately. On occasion, data must be subjected to statistical treatments and probabilities determined. The fracture toughness of pipe steel has great effect on the safety of welded pressure pipe. The fracture toughness test of circumferential welded joint was carried out in this paper for X65 pressure pipe steel. The fracture toughness experimental results were analyzed by using computer program developed by ourselves. The distribution of weld fracture toughness of X65 pressure pipe steel which may accord with normal distribution, lognormal distribution or weibull distribution can be determined by calculating the results only one time. The program, which plays an important role in structure reliability analysis, can be used to determine the probability statistic distribution of the mechanical properties. The calculated results indicate that the weld fracture toughness of the X65 pressure pipe steel can either accord with normal distribution, lognormal distribution or weibull distribution, but the optimum fitting distribution of the fracture toughness is weibull distribution.

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Fracture Assessment of Welded Joint With Geometrical Discontinuity Using the Weibull Stress

Volume 7: Operations, Applications, and Components ◽

10.1115/pvp2006-icpvt-11-94047 ◽

2006 ◽

Cited By ~ 1

Author(s):

Satoshi Igi ◽

Takahiro Kubo ◽

Masayoshi Kurihara ◽

Fumiyoshi Minami

Keyword(s):

Fracture Toughness ◽

Brittle Fracture ◽

Welded Joint ◽

Fracture Toughness Test ◽

Geometrical Condition ◽

Stress Criterion ◽

Toughness Test ◽

Fracture Assessment ◽

Geometrical Discontinuity ◽

Weibull Stress

Recently the Weibull stress is used as a fracture driving force parameter in fracture assessment. The Weibull stress is derived from a statistical analysis of local instability of micro cracks leading to brittle fracture initiation. The critical Weibull stress is expected to be a critical parameter independent of the geometrical condition of specimens. Fracture toughness test using 3-point bending and tensile tests of welded joint specimens with geometrical discontinuity were conducted in order to study the applicability of fracture assessment procedure based on Weibull stress criterion. Steel plates prepared for this study had tensile strength of 490 MPa for structural use. Two kinds of welded joint specimens, “one-bead welded joint” and “multi-pass welded joint” were prepared for fracture toughness test by using gas metal are welding. In tensile test specimen, corner flaws were introduced at the geometrical discontinuity part at where stress concentration is existed. Three dimensional elastoplastic finite element analyses were also carried out using the welded joint specimen models in order to calculate the Weibull stress. The critical loads for brittle fracture predicted by the Weibull stress criterion from CTOD test results of one-bead and multi-pass welded joint specimens show fairly good agreement with experimental results of welded joint specimens with geometrical discontinuity.

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Effects of Temperature and Strain Rate on Dynamic Fracture Toughness of Steel

Journal of the Society of Naval Architects of Japan ◽

10.2534/jjasnaoe1968.1985.158_619 ◽

1985 ◽

Vol 1985 (158) ◽

pp. 619-629 ◽

Cited By ~ 14

Author(s):

Eisuke Fujii ◽

Isamu Ohkuma ◽

Yoshiaki Kawaguchi ◽

Masatoshi Tsukamoto

Keyword(s):

Fracture Toughness ◽

Strain Rate ◽

Dynamic Fracture ◽

Dynamic Fracture Toughness ◽

Effects Of Temperature

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Manufacturing curing cycles influence on local fracture toughness properties at micro and macro scale

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/388/1/012012 ◽

2018 ◽

Vol 388 ◽

pp. 012012

Author(s):

F Lahuerta ◽

S Raijmaekers

Keyword(s):

Fracture Toughness ◽

Local Fracture ◽

Macro Scale

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Mechanical Properties and Fracture Toughness of Aluminum Vessels by Friction Stir Welding

Fracture Methodologies and Manufacturing Processes ◽

10.1115/pvp2004-2296 ◽

2004 ◽

Author(s):

Masahito Mochizuki ◽

Masao Toyoda ◽

Masayuki Inuzuka ◽

Hidehito Nishida

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Crack Initiation ◽

Base Metal ◽

Welded Joint ◽

Stir Zone ◽

Crack Initiation And Propagation ◽

Friction Stir ◽

Fine Grained ◽

Initiation And Propagation

Mechanical properties and fracture toughness in friction stir welded joint of vessels of structural aluminum alloy type A5083-O are investigated. Welded joint from 25 mm-thick plate is fabricated by one-side one-pass friction stir. Charpy impact energy and critical crack-tip opening displacement (CTOD) in friction stir weld are much higher than those of base metal or heat-affected zone, whereas mechanical properties such as stress-strain curve and Vickers hardness do not have a conspicuous difference. Effects of microstructure on crack initiation and propagation are studied in order to clarify the difference of fracture toughness between stir zone and base metal. Both tensile test and bending test show that the fine-grained microstructure in stir zone induces to increase ductile crack initiation and propagation resistance by analyzing fracture resistance curves and diameter of dimples in fracture surface. It is found that high fracture toughness value in stir zone is affected fine-grained microstructure by friction stirring.

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