Fracture toughness characterisation in the ductile-to-brittle transition and upper shelf regimes using pre-cracked Charpy single-edge bend specimens

Fatigue failure analysis of stay cables with initial defects: Ewijk bridge case study

“…The average value for K IC at room temperature, for a standardized thickness of 25 mm and for alloys with a tensile strength that agrees with the tensile strength of the wire material, is approximately K IC = 3800 N/mm 3/2 [25]. Data in [30][31] indicates that this value corresponds approximately with the border between the lower shelf and the transition zone of the temperature-dependent fracture toughness -although the chemical composition and grain structure may be different from the material used for the stay cables. For a thickness other than 25 mm, the fracture toughness at 20°C can be obtained through [25]: …”

“…c The average value for K IC originates from [25], and the standard deviation is based on the results of CTOD tests reported in [26], adjusted for the thickness according to the annex. In addition, the relatively large standard deviation is required because of the average value being on the border between the lower shelf and the transition region, as indicated in [30][31]. d The average value of C and DK 0 originate from [25].…”

Validation of constraint‐based methodology in structural integrity of ferritic steels for nuclear reactor pressure vessels

“…The trend of Δ T 0 = T 0,Ω − T 0,CT with Ω given by has already been described for the various fracture tests performed on Materials A and D. While provides a useful description of the effect of constraint loss on the ductile‐brittle transition temperature, in the case of Material A, it tends to overestimate Δ T 0 as Ω becomes increasingly negative; it also overestimates Δ T 0 in the case of biaxial bend data for Material D. An improved prediction of the behaviour of Δ T 0 with Ω for Material A and Material D may be obtained by use of for K c mat as a function of constraint in conjunction with the equation: given in Ref. [4], where ζ= 0.019 °C −1 , K 1 = 30 MPa√m and K 2 = 70 MPa√m. Using and , predictions of Δ T 0 versus Ω based on the values of α and k listed in Table 8 are presented in Figs 15 and 16 for Materials A and D, respectively.…”

“…Material A, a pressure vessel steel in the as‐received condition, was forged, quenched and tempered ferritic steel classified DIN 22NiMoCr3‐7, similar to ASTM A 508 Grade 3 Class 1, which had been taken from a reactor pressure vessel ring forging with a wall thickness of 290 mm. Material A had previously been extensively characterized and tested, 3,4 and is regarded as a European reference material. The degraded material (Material D) was an A533B ferritic steel plate, HSST Plate 14, which had been heat treated in order to produce elevated yield stress (range 620 to 655 MPa) typical of a radiation sensitive RPV steel irradiated to a fluence of 1.5 × 10 19 n/cm 2 ( E n > 1 MeV).…”

Estudo experimental do comportamento à fratura frágil em aços estruturais ferríticos e aplicações à determinação da curva mestra.

“…• Validade da metodologia da Curva Mestra para a região superior da curva de transição dúctil-frágil onde a fratura por clivagem pode ser precedida por uma grande extensão dúctil (rasgamento) da trinca, [67].…”