Showing papers on "Charpy impact test published in 2002"
TL;DR: In this article, the fracture and failure modes of α-and β-phase polypropylene homopolymers (PP-H, block- and random-type copolymers with ethylene) with high speed flexural tests and compared.
253 citations
TL;DR: In this paper, maleic anhydride-polypropylene copolymer was used to construct wood polypropylene composites with different compositions (30, 40, and 50%).
Abstract: Wood polypropylene composites (WPC) of different compositions (30, 40, and 50%) have been prepared using maleic anhydride–polypropylene copolymer of different percentage (5 and 10% relative to their wood fiber content). Tensile, flexural, fracture toughness, and impact test of the prepared WPC were carried out. From the results, it is observed that the hard wood fiber–polypropylene composites, by using maleated polypropylene (MAH-PP), show comparatively better performance to soft wood fiber–polypropylene composites. Tensile strength and charpy impact strength have been increased to a maximum of 50 and 20%, respectively. The damping index has been decreased by 60% when 10% of MAH-PP has been used. Water absorption and scanning electron microscopy of the composites are also investigated.
133 citations
TL;DR: In this paper, the authors presented materials data for the design of ITER test blanket modules with reduced activation ferritic martensitic steel type F82H as structural material from the physical properties databases, variations of modulus of elasticity, density, thermal conductivity, thermal diffusivity, specific heat, mean and instantaneous linear coefficients of thermal expansion versus temperature are derived.
131 citations
TL;DR: In this article, a non-empirical relationship between the Charpy V-notch energy CVN and the fracture toughness KIc is presented, based on the local approach.
Abstract: An attempt to establish a non-empirical relationship between the Charpy V-notch energy CVN and the fracture toughness K
Ic is presented. We focus our study on the lower shelf of fracture toughness and on the onset of the ductile-to-brittle transition of a A508 Cl.3 low alloy structural steel. The methodology employed is based on the `local approach'. Brittle cleavage fracture is modelled in terms of the Beremin (1983) model, whereas the ductile crack advance preceding cleavage in the transition region is accounted for with the GTN model (Gurson, 1977; Tvergaard, 1982; Tvergaard and Needleman, 1984. Mechanical testing at different strain rates and temperatures allowed the establishment of the constitutive equations of the material in a rate dependent formulation. Numerous fracture tests on different specimen geometries provided the large data set necessary for statistical evaluation. All specimen types were modelled with finite element analysis. Special consideration was taken in order to handle the dynamic effects in the Charpy impact test in an appropriate way. The fracture toughness could be predicted from Charpy impact test results, on the lower shelf, by applying the `local approach'. In the transition region the parameters of the Beremin model were found to deviate from those established on the lower shelf. Detailed fractographic investigations showed that the nature of `weak spots' inducing cleavage fracture changes with temperature. It is concluded that the Beremin model must be refined in order to be applicable in the ductile-to-brittle transition region.
91 citations
TL;DR: In this article, the effects of processing parameters, such as finish rolling temperature, rolling reduction, interpass time and cooling rate, on the final microstructure and mechanical properties of a grade X52 type HSLA steel has been studied by tensile and charpy impact tests and optical microscopy and scanning electron microscopy.
83 citations
TL;DR: In this article, microstructural studies and the mechanical testing (hardness, tensile and charpy tests) performed on the Eurofer’97 steel in the as-received condition and after thermal ageing treatments up to 600 °C.
80 citations
TL;DR: In this paper, the phase transformations in duplex stainless steels were identified and characterized, which occur when aging heat treatments are carried out at temperatures at which the kinetics is the fastest for the reactions mentioned.
Abstract: Duplex stainless steels, with ferritic-austenitic microstructure, have excellent mechanical properties and corrosion resistance. However, when duplex stainless steels are exposed to temperatures between 600 and 1000 °C, some phase transformations can occur such as chromium nitrides precipitation, chromium carbides precipitation and the sigma phase formation. The formation of such compounds leads to loss in both corrosion resistance and fracture toughness. The negative effects of the formation of chromium nitrides, carbides and the sigma phase are due to the chromium depletion in the matrix. The phase transformations cited above occur initially at ferritic-austenitic interfaces and at the grain boundaries. The aim of this work is to identify and characterize the phase transformations, which occur when aging heat treatments are carried out at temperatures at which the kinetics is the fastest for the reactions mentioned. At first, the samples were annealed at 1100 °C for 40 min. The aging heat treatments were then carried out at 850 °C for 6, 40 e 600 min. Microstructural characterization was done by using optical microscopy with different etchings, in order to identify each phase formed in the duplex stainless steel during aging heat treatments. The toughness was also evaluated by using Charpy impact test. Impact tests show that loss of toughness was related to phase transformations.
73 citations
25 Sep 2002-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the authors examined the relationship between fracture energy and the ductile area measured on the fracture surface and found that the area situated next to the notch is correlated with fracture energy for all temperatures.
Abstract: The aim of this study is to examine the relationship between fracture energy and the ductile area measured on the fracture surface. Instrumented Charpy tests and fracture toughness tests are performed in the transition temperature range, as well as at lower temperatures. Quantitative fractographic analyses of Charpy specimens reveal a certain proportion of ductile fracture even if the Charpy test is conducted at low temperatures, below the transition temperature. The ductile fracture area situated next to the notch is correlated to fracture energy for all temperatures. In the transition temperature range, fracture energy and the ductile area have a large scatter. Since the limiting event in the development of the ductile area is the initiation of cleavage, the maximum principal stress has been computed in different specimens using the finite element method. It has been shown that the propagating ductile crack does not increase the stress level, but does increase the probability of cleavage fracture through an expansion of the plastic volume where weak points can be found.
64 citations
TL;DR: In this article, a new method has been developed involving direct measurement of the load-line displacement during instrumented Charpy testing, which uses a laser interferometer to measure displacement in addition to the loadline displacement derived from the load signal.
58 citations
TL;DR: In this article, the effect of W, Ta, and Cr composition on the tensile and Charpy properties of the reduced-activation ferritic/martensitic steels was examined.
TL;DR: In this paper, a ball punch test technique was used to evaluate the conventional tensile and impact properties of the tempered martensitic steel EUROFER97 from room temperature down to liquid nitrogen temperature.
TL;DR: In this paper, the toughness of the weld heat-affected zone microstructures of a 9Cr-1Mo steel has been studied with simulated samples, showing that the highest toughness in terms of the highest upper-shelf energy and lowest ductile-to-brittle transition temperature have been observed in the intercritical region.
TL;DR: In this article, a large effort was put into taking advantage of the test instrumentation allowing for load versus time recording during the whole test, which can be used as input to micromechanical modeling of the static as well as dynamic initiation fracture toughness trends.
Abstract: The Charpy impact test is extensively used in the surveillance programs to monitor neutron reactor pressure vessel degradation induced by neutron irradiation. The energy absorbed during the test is the main parameter used for engineering characterization of thematerials. At SCK·CEN, a large effort was put into taking advantage of the test instrumentation allowing for load versus time recording during the whole test. Analysis of the load—time trace allows to determine a number of key parameters, in particular, the flow properties, the microcleavage fracture stress, the crack arrest performance and the characteristic transition temperatures which aremore physically grounded than conventional indexing to fixed absorbed energy or lateral expansion levels. Combination of static tensile tests with instrumented Charpy impact tests allows for establishing the so-called stress diagram. This can be used as input to micromechanical modeling of the static as well as dynamic initiation fracture toughness trends. Furthermore, the Charpy arrest load correlates well to the nil ductility temperature as determined from the Pellini drop weight test and allows concurrent application of a crack arrest safety approach. As it will be illustrated by relevant examples, a significant advantage of the above considerations is that they allow to incorporate a physically grounded understanding of irradiation effects into the evaluation of reactor vessel integrity.
01 Jan 2002
TL;DR: In this article, the influence of common steel impurities on steel mechanical properties is discussed. But the influence is not limited to typical impurities, but also to trace elements such as As, Sn, Sb, Se, Cu, Pb, and Bi.
Abstract: The demand for cleaner steels increases every year. In addition to lowering non-metallic oxide inclusions and controlling their morphology, composition and size distribution, clean steel requires lowering other residual impurity elements such as sulfur, phosphorus, hydrogen, nitrogen and even carbon [1, , and trace elements such as As, Sn, Sb, Se, Cu, Pb, and Bi. Table I lists the influence of common steel impurities on steel mechanical properties . Table I Influence of typical impurities on mechanical properties [1] Element Form Mechanical properties affected S,O Sulfide and oxide inclusions • Ductility, Charpy impact value, anisotropy • Formability (elongation, reduction of area and bendability) • Cold forgeability, drawability • Low temperature toughness • Fatigue strength Solid solution • Solid solubility (enhanced), hardenability Settled dislocation • Strain aging (enhanced), ductility and toughness (lowered) Pearlite and cementite • Dispersion (enhanced), ductility and toughness (lowered) C,N
TL;DR: In this article, the results from three methods of measuring the fracture toughness are presented and discussed: Charpy V-Notch testing, small punch testing and full size K Ic testing.
TL;DR: In this article, the authors reported the experience within the ESB regarding small punch testing of various plant components including steam drums, rotors and turbine bolts, and showed that a reasonable relationship existed between the Charpy FATT and the small punch transition temperature, TSP.
TL;DR: In this paper, a steel with 14 mm thickness in quenched and tempered condition was shielded metal arc welded (SMAW) with 2 kJ/mm heat input using basic flux coated filler rods without any pre or post welding heat treatments.
Abstract: HSLA-100 steel with 14 mm thickness in quenched and tempered condition was shielded metal arc welded (SMAW) with 2 kJ/mm heat input using basic flux coated filler rods without any pre or post welding heat treatments. The steel was found to be welded satisfactorily in this condition without developing any defect. Optical microscopy studies revealed typical cast dendritic structure in the weld metal and coarse bainite in grain-coarsened area of the heat-affected zone (HAZ). Transmission electron microscopy (TEM) study confirmed incidence of mixed structure of martensite laths and bainite in weld metal, while, it was mainly of bainite laths in HAZ with evidence of martensite–austenite (M–A) constituent and massive ferrite. The yield strength (YS), ultimate tensile strength (UTS) and Charpy V-notch (CVN) impact energy of the weld metal (YS-695 MPa, UTS-842 MPa and CVN-105 J at –50°C) and HAZ (YS-790 MPa, UTS-891 MPa and CVN-130 J at –50°C) were found satisfactory although HAZ properties were inferior to the base metal properties. The hardening of HAZ was not very significant in this steel under the present welding condition.
TL;DR: In this article, the dynamic behavior of three different fiber fabric composite laminates was studied by testing notched specimens in an instrumented Charpy machine, and the registered impact force and displacement at the specimen hammer contact point were used to evaluate Mode-I fracture energy and dynamic fracture toughness.
TL;DR: In this article, the results of J-R tearing resistance tests, characterized by crack initiation resistance J0.2 and tearing modulus dJ/da relative to a base metal (A48 French standard steel) and manual metal arc deposited metals are presented and discussed.
TL;DR: In this article, the size dependence of the upper shelf energy (USE) and the ductile-to-brittle transition temperature (DBTT) in the Charpy V-notch test is investigated.
Abstract: Issues related to the size dependence of the upper shelf energy (USE) and the ductile-to-brittle transition temperature (DBTT) in the Charpy V-notch test are investigated. Emphasis is placed on the interplay between inertial, strain rate hardening, strain hardening, thermal softening and material length scale effects. Geometrically similar specimens are considered first. For such specimens, the ductile-to-brittle transition temperature is found to increase with specimen size, with the amount of the increase depending on the material properties. To model available experiments, calculations are also carried out for Charpy specimens where only the ligament size is varied and two classes of pipe steels are considered. For a relatively high strength pipe steel, the experimental results exhibit no size dependence of the DBTT. On the other hand, a significant shift in the DBTT is obtained for a low strength steel. The numerical studies are used to understand the difference between these two classes of steels. The extent to which the size effect is material dependent is investigated.
TL;DR: The tensile, impact and bending properties of CaCO3 filled acrylonitrile-butadiene-styrene copolymer (ABS) composites were measured at room temperature as mentioned in this paper.
Abstract: The tensile, impact and bending properties of calcium carbonate (CaCO3) filled acrylonitrile-butadiene-styrene copolymer (ABS) composites were measured at room temperature. It was found that the tensile modulus increased nonlinearly with increasing the weight fraction φ + of the fillers, and the tensile strength and tensile fracture stress decreased gently with the increase of. The Charpy notched impact strength decreased quickly when φ≤ 10%, and then decreased gently with increasing φ. While the bending strength increased when φ≤ 10%, and then it decreased gradually with increasing φ. However, the effects of filler size and its surface treatment on these mechanical properties were insignificant. Furthermore, the Vicat softening temperature (TV) of the samples was measured at a constant loading and a temperature ramp rate. The result showed that TV increased with the addition of. It indicates that CaCO3 fillers are beneficial to improve the heat resistant properties of the resin.
TL;DR: In this paper, a probabilistic model was used to predict the temperature dependence of cleavage fracture toughness for 2Cr-Ni-Mo-V pressure vessel steel in the initial and highly embrittled state.
TL;DR: In this article, the influence of post-weld heat treatment (PWHT) on hardness, microstructure, and impact properties were investigated for gas-tungsten-arc (GTA) weld joints.
TL;DR: In this paper, a model has been produced to describe irradiation damage in high nickel submerged arc welds (1.6% Ni, 1.5% Mn, 0.5%, and 0.6%) irradiated in materials test reactors.
TL;DR: In this paper, the fracture energy of notched Charpy A508 steel specimens was determined from the incident, reflected and single wire fracture gage signals, and it was shown that fracture occurs relatively early and prior to the taking off of the bar by rigid body motion.
Abstract: This paper reports our methodology and results for the assessment of the dynamic fracture energy of notched Charpy A508 steel specimens. The fracture tests consist of one-point bend impact applied to the specimen in contact with an instrumented bar. Fracture is caused by the inertia of the unsupported specimen only. The fracture energy is determined from the incident, reflected and single wire fracture gage signals. High-speed photographic recordings show that for all the specimens investigated in the “lower shelf” temperature regime, fracture occurs relatively early and prior to “taking off” of the bar by rigid body motion. It also confirms that the fracture gage readings indeed coincide with the formation of a crack from the notch tip.
TL;DR: Charpy V-notch impact toughness of 600 MPa yield stress TMT rebars alloyed with copper, phosphorus, chromium and molybdenum has been evaluated as mentioned in this paper.
Abstract: Charpy V-notch impact toughness of 600 MPa yield stress TMT rebars alloyed with copper, phosphorus, chromium and molybdenum has been evaluated. Subsize Charpy specimens were machined from the rebar keeping the tempered martensite rim intact. The copper-phosphorus rebar showed toughness of 35 J at room temperature. The toughness of copper-molybdenum and copper-chromium rebars was 52 J. The lower toughness of phosphorus steel is attributed to solid solution strengthening and segregation of phosphorus to grain boundaries. Due to superior corrosion resistance, copper-phosphorus TMT rebar is a candidate material in the construction sector.
TL;DR: EUROFER97 as discussed by the authors is a 9CrWVTa reduced-activation ferritic-martensitic (RAFM) steel, modelled after the conventional T91 alloy (9Cr-1Mo-0.2V−0.08Nb); some of the elements in T91 that will transmute in a fusion neutron spectrum into high energy radiation emitters with long-half life have been selectively replaced by other elements (W has replaced Mo and Ta has replaced Nb).
TL;DR: The impact test method based on a pendulum, generally called the Charpy test, is one of the more cost-effective material testing procedures, both with respect to acceptance of products and to surveillance.
Abstract: The impact test method based on a pendulum, generally called the Charpy test, is one of the more cost-effective material testing procedures, both with respect to acceptance of products and to surveillance. This contribution attempts to present a brief historical review about the general development of material testing, starting at the beginning of the intense industrialisation in the second half of the 19th century, and tries to point out the role and the position of impact testing during this period. Several periods in the evolution of impact testing based on a pendulum are discussed in detail.
01 Sep 2002-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the authors used the notched specimen technique to overcome the difficulties in introducing fatigue precrack to small fracture-tough specimens, and the results corrected from the results of notched specimens were very consistent with the results obtained from precracked specimens.
Abstract: As a part of small specimen testing techniques, the notched specimen technique is studied to overcome the difficulties in introducing fatigue precrack to small fracture toughness specimens. It was noted that stress triaxiality and the plastic constraint ahead of a notch root decreased with increasing notch root radius ( ρ ). Considering that the applied stress at the notch tip is redistributed and relaxed due to the increased plasticity, the fracture toughness obtained from notched specimens was corrected. Fracture toughness testing was conducted using an instrumented impact and a static three-point bending tester. The specimens had notch root radii which ranged from a fatigue precrack to a Charpy notch root radius of 250 μm. Fracture toughness values corrected from the results of notched specimens were very consistent with the plane strain fracture toughness obtained from precracked specimens. In addition, a limiting notch root radius ( ρ 0 ), below which the fracture toughness was independent of ρ , was observed. To investigate this phenomenon, the fracture surface was observed with a scanning electron microscope (SEM).