Jesús Toribio

• Professor
• University of Salamanca

This paper focuses on the study of the tensile fracture behaviour of prismatic notched specimens of cold drawn pearlitic steel, providing a macro- and micro-approach. Two types of notched samples with very different notch radius (sharp and blunt notches, PAA and PCC) and the same notch depth were studied, thereby allowing a study of the fracture be...

Dear Colleagues, We cordially invite you to participate in the Thematic Symposium ESIS TC10 “Environmentally Assisted Cracking and Hydrogen Embrittlement” at the ECF24, August 26 - 30, 2024. Zagreb, Croatia. Sincerely, Symposium Chairs

In this paper, stress intensity factor (SIF) solutions of eccentric annular external cracks in elliptical notched round bars under tension loading have been obtained from 3D finite element analysis, along with their relation to the energy release rate obtained with the J-integral contour. The analysis variables have been the ligament diameter, its...

The final aim of this paper is to study the microstructural changes in the necking region of progressively cold-drawn pearlitic steel wires by means of a thorough and detailed analysis of pearlite interlamellar spacing and Vickers micro-hardness in this special region. To this end, a set of progressively cold-drawn pearlitic steel wires belonging t...

This paper studies the hydrogen-assisted microdamage (HAMD) in fully-pearlitic steel. A detailed analysis is provided of the HAMD region in axisymmetric round-notched samples of high-strength eutectoid pearlitic steel under hydrogen embrittlement environmental conditions. The microscopic appearance and evolution of the hydrogen affected region is a...

Cold drawing is a commonly used technique for manufacturing the prestressing steel wires used as structural elements in prestressed concrete structures. As a result of this manufacturing process, a non-uniform plastic strain and residual stress states are generated in the wire. These stress and strain fields play a relevant role as the main cause o...

This paper studies the drawing-induced intercolonial microdamage (ICMD) in pearlitic microstructures. The analysis was performed from the direct observation of the microstructure of the progressively cold-drawn pearlitic steel wires associated with the distinct steps (cold-drawing passes) of a real cold-drawing manufacturing scheme, constituted by...

In this paper, the effects of the skin pass technique on the residual stress and plastic strain fields generated in cold drawn pearlitic steel wires are analyzed. The aim is to find out the optimal conditions to be used in the design of a manufacturing process for obtaining more reliable structural components in terms of the main cause of failure:...

In this paper, a numerical modeling was developed to study (on the basis of the Paris law) the fatigue propagation paths of eccentric external (outer) cracks in circumferentially cracked round bars (CCRB) subjected to a cyclic type of loading in the form of either remote tensile loading or imposed axial displacement. Results show how the eccentrici...

The main cause of in-service failure of cold drawn wires in aggressive environments is hydrogen embrittlement (HE). The non-uniform plastic strains and residual stresses generated after cold drawing play a significant role in the matter of HE susceptibility of prestressing steels. In this paper, a new and innovative design of the drawing scheme is...

Round-notched samples are commonly used for testing the susceptibility to hydrogen embrittlement (HE) of metallic materials. Hydrogen diffusion is influenced by the stress and strain states generated during testing. This state causes hydrogen-assisted micro-damage leading to failure that is due to HE. In this study, it is assumed that hydrogen diff...

In this paper, stress intensity factor (SIF) solutions are numerically obtained for notched bars subjected to tensile loading containing an eccentric circular inner crack located in the cross-section corresponding to the notch root. The finite element method and the J-integral have been used to obtain the SIF and to analyze the effect on it of thre...

There are many inventions to avoid the risk of electric contact in the plug. However, the objective of the invention resulting from the research is the proposal of a complementary measure to the existing ones, solving the specific problem of electrocutions that occur in the action of connection and disconnection, due to the contact of the user with...

This scientific article offers an innovative approach to fatigue crack growth in progressively cold drawn pearlitic steels that exhibit a microstructurally-induced tortuous propagation path (zig-zag fatigue crack path). The proposed novel approach, Toribio-González-Matos (TGM) model, consists of a modified Paris Law including the real fatigue crack...

This paper offers a kinematic fracture criterion for hydrogen embrittlement (or hydrogen assisted cracking) of cracked samples of high strength pearlitic steel tested at very different loading/straining rates under cathodic electrochemical conditions promoting hydrogen entry and diffusion into the specimens. The local strain rate at the crack tip (...

This paper offers a kinematic fracture criterion for hydrogen embrittlement (or hydrogen assisted fracture) of notched samples of high strength pearlitic steel tested at very different loading/straining rates under cathodic electrochemical conditions promoting hydrogen entry and diffusion into the specimens. The local strain rate at the notch tip (...

This paper tries to advance towards a new concept of crack path covering different length scales (multi-scale approach) and distinct points of view (multi-perspective approach). With regard to the fracture/crack path profile in a vertical plane of analysis (i.e., perpendicular to the crack front), it can be studied by means of fracto-materialograph...

A fracture mechanics approach to hydrogen-assisted microdamage and failure analysis of high-strength pearlitic steel wires is presented. Fractographic analysis revealed micromechanical effects of hydrogen in the form of tearing topography surface(TTS). The progress of this microdamage is modelled as a macroscopic crack that extends the original fat...

Hydrogen-assisted fatigue crack growth (corrosion-fatigue) is studied in corner cracks emanating from holes placed in plates under tensile loading, comparing the results with those obtained in the case of fatigue in air. To this end, numerical modeling has been carried out to evaluate the crack front advance based on the Paris equation and the stre...

This paper analyses hydrogen assisted cracking (HAC) paths in cold drawn pearlitic steels in which progressive cold drawing produces a preferential orientation of the pearlitic microstructure in the matter of colonies and lamellae, thereby inducing strength anisotropy in the steel, and thus the resistance to HAC is a directional property that depen...

This paper presents stress intensity factor (SIF or K) solutions for a semi-elliptical surface crack in a bolt subjected to remote tension and nut loading. Solutions were numerically computed by a 3D finite element method (FEM) with quarter-point singular isoparametric elements along the crack line. The SIF was calculated through the stiffness deri...

Crack path deflection is a phenomenon appearing in cold-drawn pearlitic steel wires as a consequence of the pearlite microstructure orientation induced by the manufacturing procedure, the deflection angle being approximately 90º, thereby representing a crack propagation step (fracture wall), a signal of splitting, delamination or debonding in the f...

This paper offers a multiscale approach (macro & micro) to the fatigue crack paths in progressively cold drawn pearlitic steels, with emphasis on the relationship between the pearlitic microstructure of the steels (progressively oriented as a consequence of the manufacturing process by cold drawing) and the fatigue behaviour at the macro- and micro...

This article studies plasticity-induced fatigue crack growth retardation in metals caused by crack path bifurcation in the near-tip region. To this end, the finite element method was used to model the crack with its bifurcated tip under several stress intensity factor (SIF) ranges. The results show the appearance of a retardation effect in the fati...

In this paper, a numerical modelling was developed to study (on the basis of the Paris law) the fatigue propagation paths of eccentric external cracks in circumferentially-cracked round bars (CCRB) subjected to axial displacement. Results demonstrate how the eccentricity (in relation to the wire axis) of the circular resistant ligament increases wi...

This article studies the plasticity-induced fatigue crack growth retardation in a steel caused by crack path deflection in the near-tip region. To this end, the finite element method was used to model the crack with its deflected kink. The results allow a calculation of the fatigue crack propagation rate for the two analyzed crack configurations, i...

This paper analyses stress corrosion cracking (SCC) paths in cold drawn pearlitic steels in which progressive cold drawing produces a preferential orientation of the pearlitic microstructure in the matter of colonies and lamellae, thereby inducing strength anisotropy in the steel, and thus the resistance to SCC is a directional property that depend...

This paper analyses the anisotropic fracture behaviour exhibited by initially-smooth samples of cold drawn pearlitic steel wires (commercial prestressing steel wires) subjected to tensile tests in aggressive environment promoted by a corrosion cell. Two testing rates were used: one moderately fast (0.1 mm/min) and another moderately slow (0.01 mm/m...

This paper is directed towards a new concept of structural integrity, including a novel and forward-looking approach, and broadening the amplitude of the definition, thereby offering a multi-scale analysis comprising and covering all length scales in the theoretical framework of the new terms of giga-, mega-, macro-, micro- and nano-structural inte...

The cleaning of the ear canal is very important, and it is crucial that it is performed by an otolaryngologist as it requires a high level of competence and skill. The accumulation of cerumen or earwax in the ear canal is one of the most commonly observed problems in patients, and ignoring it may cause hearing loss, irritation and discomfort. There...

This paper develops other by the author on a novel and forward-looking approach to the concept of structural integrity, comprising and covering all length scales in the theoretical framework of the innovative terms of giga-, mega-, macro-, micro- and nano-structural integrity, and thus the science of fracture mechanics & structural integrity can be...

This paper analyses the role of non-metallic inclusions in the fracture behaviour of high-strength cold-drawn pearlitic steel wires. To this end, a metallographic and scanning electron microscope (SEM) analysis was performed of the microstructural defects in pearlitic steels and their evolution with the manufacturing process by cold drawing, analys...

This article focuses on the analysis of the evolution of inclusions present in eutectoid pearlitic steel subjected to a real cold drawing process. To this end, wires belonging to different stages of the manufacture chain were studied, starting from an initial hot rolled bar (not cold drawn at all). In addition to the information obtained through vi...

This paper offers a detailed analysis of the hydrogen-assisted micro-damage (HAMD) region in axisymmetric round-notched samples of high-strength eutectoid pearlitic steel under hydrogen embrittlement environmental conditions. Emphasis is placed on the microscopic appearance and the evolution of such a microscopic topography from the initiation (sub...

This paper presents a combined micro- and macro-approach to the fracture of high-strength pearlitic steel bars subjected to multiaxial stress states produced by notches of very different geometries. A fracture criterion based on the distortional part of the strain energy density (or, accordingly, the equivalent stress in the von Mises sense) averag...

This paper offers an innovative and unconventional approach to the relationship between painting and fracture mechanics on the basis of previous research of the author in the field of fracture and structural integrity of cold drawn pearlitic steel in inert and aggressive environments (environmentally assisted cracking, stress corrosion cracking, hy...

This paper offers a numerical modeling of hydrogen embrittlement and notch tensile strength of high-strength pearlitic steel (supplied in the form of hot rolled bars) in the presence of blunt notches, by using the finite element method in order to determine how the notch depth influences the concentration of hydrogen in the steady-state regime for...

This paper offers an innovative and unconventional approach to the relationship between cinema and fracture mechanics on the basis of previous research of the author in the field of fracture and structural integrity of cold drawn pearlitic steel in the presence of notches, in addition to the analysis of fracture crack paths, in the conceptual frame...

This paper offers an innovative and unconventional approach to the relationship between poetry and fracture mechanics on the basis of previous research of the author in the field of fatigue & fracture crack paths in progressively cold drawn pearlitic steel, in the conceptual framework of his thoughts and reflections about the philosophy of arts and...

In this paper a study is presented of the fracture behaviour in the presence of notches of high-strength pearlitic steel with different cold drawing degree. To this end, axisymmetric notched samples with a circumferentially-shaped notch of very distinct geometries (sharp and blunt, deep and shallow) were taken from wires with different levels of dr...

This article focuses on the analysis of the evolution of inclusions present in eutectoid pearlitic steel subjected to a real cold drawing process. To this end, wires belonging to different stages of the manufacture chain were studied, starting from an initial hot rolled bar (not cold drawn at all). In addition to the information obtained through vi...

This article deals with the influence of the crack path branching (at the micro level) on the plasticity-induced fatigue crack growth. With regard to this, a modeling by means of the finite element method was performed considering a cracked panel subjected to tension with different symmetric and asymmetric configurations of the bifurcated crack tip...

In this paper an exhaustive scientific work is performed, by means of metallographic and scanning electron microscope (SEM) techniques, of the microstructural defects exhibited by pearlitic steels and their evolution with the manufacturing process by cold drawing, analyzing the consequences of such defects on the isotropic/anisotropic fracture beha...

The aim of this study is to obtain the stress intensity factor (SIF) along the crack front of elliptical cracks located in finite-thickness plates subjected to imposed displacement or applied tensile load, for different crack geometries (relative depths and aspect ratios) and crack configurations (embedded, surface, and corner). The SIF was calcula...

In this study, hydrogen-assisted fatigue propagation (a kind of corrosion fatigue phenomenon) in corner cracks at holes located in plates under tensile loading was studied, the results compared with those obtained for propagation by fatigue in air. To this end, numerical modeling was carried out for the case studied to evaluate the advance of the c...

This article studies the retardation effect in plasticity-induced fatigue crack growth rate for a low-medium strength steel, due to the appearance of microdeflections in the crack path. To this end, the finite element method was used to model the crack with its kinked tip under several stress intensity factor (SIF) ranges. The results allowed a cal...

The fracture performance of axisymmetric notched samples taken from pearlitic steels with different levels of cold-drawing is studied. To this end, a real manufacture chain was stopped in the course of the process (on-site in the factory), and samples of all intermediate stages were extracted from the initial hot-rolled bar (not cold-drawn at all)...

This paper evaluates, by quantitative fractography and image analysis techniques, the hydrogen embrittlement and microdamage in notched samples of 316L steel, the described phenomenon affecting the structural integrity, durability and safety of the pipelines made with such a material. After the hydrogen embrittlement tests, it is seen that microdam...

The model describing the corrosion-mechanical fracture of the underground gas pipeline with semi-elliptical external surface crack is developed taking into account the intensification of crack growth in the pipe steel 17H1S by diffusible hydrogen. The model is grounded on the energy approach to fracture combined with the hydrogen accelerated soil c...

Prestressing steel wires usually undergo cyclic loading in service. Therefore, it is of interest to analyse certain features of their mechanical behaviour under this type of loading, such as the Bauschinger effect (BE) or the hardening rule, that fit the real mechanical behaviour appropriately. In this study, different samples of high strength pear...

This paper provides a definition and identification of a new (non-conventional) microstructural unit in cold drawn pearlitic steel: the pearlitic pseudocolony, a special pearlitic colony in which the lamellae are not oriented along the wire axis or cold drawing direction (contrarily to what happens in the normal conventional colonies), thereby prod...

Progressive cold drawing in eutectoid steel produces a preferential orientation of pearlitic colonies and ferrite/cementite lamellae, thus inducing strength anisotropy in the steel and mixed mode propagation. While in the hot rolled steel (not cold drawn) the pearlitic microstructure is randomly oriented and the crack progresses in hydrogen by brea...

This paper offers a novel and forward-looking approach to the concept of structural integrity, comprising and covering all length scales in the conceptual framework of the innovative concepts of mega-, macro-, micro- and nano-structural integrity, and thus the science of fracture mechanics & structural integrity can be considered as a branch of mat...

Cold drawn pearlitic steels posses a hierarchical microstructure consisting of pearlitic colonies (first microstructural level) and pearlite (ferrite/Fe & cementite/Fe3C) lamellae (second microstructural level) that evolves during the manufacturing process by cold drawing towards a preferential orientation aligned in the drawing (wire axis) directi...

This paper offers an innovative and unconventional approach to the relationship between art and fracture mechanics on the basis of previous research of the author in the field of fracture and structural integrity of cold drawn pearlitic steel and in the conceptual framework of his thoughts and reflections about the philosophy of arts and humanities...

In this study, fracture surfaces of notched specimens of pearlitic steels subjected to constant extension rate tests (CERTs) are analyzed, in an environment causing hydrogen assisted fracture. In order to obtain general results, both different notched geometries (to generate quite distinct stress triaxiality distributions in the vicinity of the not...

This paper analyses both fatigue & fracture crack paths generated by manufacturing-induced microstructural & strength anisotropy in cold drawn pearlitic steels, on the basis of their microstructural evolution during manufacturing by multi-step cold drawing that produces slenderizing and orientation of the pearlitic colonies, together with densifica...

This paper analyses the fatigue and fracture behavior of a steel with quasi-eutectoid composition (slightly hypereutectoid) and spheroidized microstructure. The fatigue crack surface showed ductile micro-tearings produced by propagating the crack through the thin layer of proeutectoid cementite. The fracture is initiated at the fatigue crack tip in...

This paper offers a palimpsestus approach to the multiscale microstructural evolution in progressively cold drawn pearlitic steel, analyzing in particular the evolution with cold drawing of: (i) the prior austenitic grain (zero, or virtual, microstructural level); (ii) the pearlitic colony (first microstructural level); (iii) the pearlite lamellae...

Prestressing steel wires are manufactured by cold drawing during which a preferential orientation is achieved in the matter of pearlitic colonies and lamellae. In addition to this general trend, special (unconventional) pearlitic pseudocolonies evolve during the heavy-drawing manufacture process affecting the posterior macro-, micro- and nano-struc...

This paper deals with the concept of micro-fracture map (MFM) and its role in structural integrity evaluations in materials science and engineering, on the basis of previous research by the author on notch-induced fracture and hydrogen embrittlement of progressively cold drawn pearlitic steels and 316L austenitic stainless steel. With regard to thi...

Progressive cold drawing in eutectoid steel produces a preferential orientation of pearlitic colonies and ferrite/cementite lamellae, thus inducing strength anisotropy in the steel and mixed mode propagation. While in the hot rolled steel (not cold drawn) the pearlitic microstructure is randomly oriented and the crack progresses in hydrogen by brea...

This paper offers a numerical approach to the problem of hydrogen embrittlement and notch tensile strength of sharply notched specimens of high-strength pearlitic steel supplied in the form of hot rolled bars, by using the finite element method in order to determine how the notch depth influences the concentration of hydrogen in the steady-state re...

This paper studies the notch-induced anisotropic fracture behaviour in progressively cold drawn pearlitic steels. The necessity is emphasized of both stress triaxiality (constraint) and microstructural anisotropy (orientation) to induce anisotropic fracture behaviour in the pearlitic steel wires. A materials science approach to the phenomenon is pr...

This paper offers a macro- and micro-approach to locally multiaxial fatigue crack paths in oriented and non-oriented pearlitic microstructures, addressing the important role of microstructural evolution (orientation and packing closeness) during the manufacture process by cold drawing in the posterior fatigue performance of the pearlitic steel wire...

In this paper, stress intensity factor (SIF) was calculated in a bar subjected to tensile loading, considering a circular inner crack that exhibited certain eccentricity in relation to the cylinder axis. The computation was performed by means of the finite element method (FEM) using a three dimensional (3D) model and the J-integral, the analyzed va...

The aim of this paper is to analyze the effect of diverse cyclic loading conditions on the residual stress field in cold-drawn pearlitic steel wires. To this end, on one hand, a numerical simulation by the finite element method of the manufacturing process (cold drawing) of a prestressing steel wire was carried out for revealing the residual stress...

Crack paths in cold drawn pearlitic steels are affected by microstructural anisotropy generated by cold drawing in the form of markedly oriented microstructure in the matter of pearlite colonies and lamellae, thus inducing strength anisotropy in the steel, crack path deflection and mixed mode propagation. This paper establishes a conceptual connect...

The calculation model is developed to evaluate the residual lifetime of a pipe with a crack considering in-service degradation of the pipeline steel and the effect of soil corrosion. The model is based on the first law of thermodynamics. The problem of determination of the period of subcritical crack growth in a pipe is reduced to the differential...

Wind turbines are key elements in the field of renewable energies. They can be considered as engineering evolutions of old-fashion windmills appearing in the master work by Miguel de Cervantes: Don Quijote de la Mancha. The main subject of this paper is related to fracture behaviour and structural integrity of cold drawn pearlitic steel wires for w...

This paper analyzes the influence of the presence of notches on the stress intensity factor (SIF) of round bars with circumferential cracks subjected to tension loading. The finite element method (FEM) together with the computation of the J-integral were used to calculate the SIF in both the circumferentially-cracked round bar (CCRB) and the circum...

This paper analyzes the hierarchical microstructure of cold-drawn pearlitic steels. To this end, environmentally assisted fracture behavior and microstructural integrity in aggressive environments is analyzed in progressively cold-drawn pearlitic steels based on their microstructural evolution during the multi-step cold drawing manufacture process...

This paper reviews previous research by the author in the field of hydrogen effects on progressively cold-drawn pearlitic steels in terms of hydrogen degradation (HD), hydrogen embrittlement (HE) or, at the micro-level, hydrogen-assisted micro-damage (HAMD), thus affecting their microstructural integrity and compromising the (macro-)structural inte...

This paper deals with the microstructure-based anisotropic fatigue behavior of hot rolled and cold drawn pearlitic steel wires, showing that: (i) the corresponding fatigue crack paths in both the hot rolled bar and the heavily cold drawn wire develop in global mode I in both materials, i.e., no macroscopic (apparent) anisotropic effect arise in the...

This paper deals with the directional toughness and anisotropic fracture behavior of progressively cold drawn pearlitic steel wires on the basis of their microstructural evolution during manufacturing by multi-step cold drawing that produces slenderizing and orientation of the pearlitic colonies, together with densification and orientation of the F...

This paper deals with notch-induced anisotropic fracture behavior of progressively cold drawn pearlitic steels on the basis of their microstructural evolution during manufacturing by multi-step cold drawing that produces slenderizing and orientation of the pearlitic colonies, together with densification and orientation of the Fe/Fe3C lamellae, revi...

This papers deals with fracture behavior and structural integrity of progressively cold-drawn pearlitic steels on the basis of their microstructural evolution during manufacturing by multi-step cold drawing. It is seen that the manufacture technique by progressive cold drawing in several steps produces a microstructural evolution in the form of pro...

Progressive cold drawing in eutectoid steels produces a preferential orientation of the pearlitic microstructure in the wire axis or drawing direction. This affects the posterior behaviour of the steels under conditions of stress corrosion cracking (SCC). The experimental results show that cold drawing induces strength anisotropy in the steel, and...

This paper reviews previous research by the author in the field of hydrogen effects on progressively cold-drawn pearlitic steels in terms of hydrogen degradation (HD), hydrogen embrittlement (HE) or, at the micro-level, hydrogen-assisted micro-damage (HAMD), thus affecting their microstructural integrity and compromising the (macro-)structural inte...