Effect of Q&P Process on 0.15C-MnSi Steels

The present study is focused on analyzing the effect of Mn amount on two experimental steel compositions, specially designed for Q&P (Quenching and Partitioning), 0.15C-2.5Mn-1.5Si and 0.15C-3Mn-1.5Si without significant contribution of Al. Two-Step Q&P thermal treatments were performed at laboratory scale in a quenching dilatometer Bähr DIL805A/D. The fractions of retained austenite were evaluated by X-ray diffraction techniques. The mechanical properties of the Q&P samples were evaluated, a strong dependence of strength, uniform elongation and strain hardening values on process parameters has been found. Higher uniform elongation were related to higher residual austenite contents. The 0.15C-3Mn-1.5Si steel showed systematically the largest mechanical values with respect to the 0.15C-2.5Mn-1.5Si steel.Peer ReviewedPostprint (published version

Quenching and tempering (Q&T) effect on a steel for forging with Cr and Mo addition

The effect of heat treatment on the mechanical behavior of a 0,20 % steel with Cr and Mo addition is here reported. Such steel can just target the mechanical properties achievable by its intrinsic hardenability. Aim of this paper is to evaluate the mechanical behavior dependence as a function of different quenching and tempering (Q&T) treatments. Results show that, after Q&T, the material can target a - 20°C fracture appearance transition temperature (50% FATT) measured by a Charpy-V impact test making this steel suitable for low temperature application

Does partial tear repair of adjacent tendons improve the outcome of supraspinatus tendonfull-thickness tear reinsertion?

AbstractBackgroundPartial tearing of the infraspinatus and/or subscapularis tendon(s) is frequently associated with supraspinatus full-thickness tears. However, limited data regarding its influence on supraspinatus surgical repair is available.PurposeOur aim was to assess the functional and anatomical outcomes of open repair of supraspinatus full-thickness tears combined with adjacent partial tearing, comparatively to a control.MethodsWe retrospectively identified 22 patients (22 shoulders) with a partial tear, most of them being a delamination tear, of the infraspinatus and/or subscapularis tendons associated with a complete detachment of the supraspinatus tendon. Twenty-seven patients (27 shoulders) treated for an isolated complete detachment of the supraspinatus tendon by open repair served as controls. The mean age was 58 years. A proximalized trans-osseous reinsertion of the supraspinatus tendon was combined with a curettage-closure of the delamination tear. Patients were evaluated with standardized MRI at last follow-up.ResultsAt a mean of 75-month follow-up, the presence of a partial tear of either infraspinatus or subscapularis, or both, did not influence function and healing rates of supraspinatus tendon repair. Conversely to the control, when a retear occurred, the functional score tended to worsen. Preoperatively, fatty muscular degeneration was more pronounced when a partial tear was present. Fatty degeneration worsened regardless of repair healing.ConclusionOpen reinsertion of a supraspinatus full-thickness tear associated with a thorough treatment of partial tear of adjacent tendons led to optimal functional and anatomical mid term outcomes. Our results suggest the presence of a partial tear of adjacent tendons could be associated with poorer function in case of supraspinatus tendon re-rupture.Level of evidenceLevel III case-control study

Corrosion behaviour of high temperature fuel cells: Issues for materials selection

The corrosion of alloy components in fuel cell is recurring issue and currently it has been leading to low performances of fuel cell and failures. This issue is more prominent in high temperature systems such as molten carbonate and solid oxide fuel cell which operate above 600 °C. The cathode side and anode side corrosion issues have been addressed by many groups but components like current collectors have not. In this framework materials selection is a key issue. Comparing different experiments it can be concluded that the choice of stainless steel (SS) is good choice. In particular, SS316L is good choice but long term test show high degradation of the components. This degradation is mainly due to migration (diffusion) of elements in oxide layer and in base material. Therefore, further studies are needed in order to deeply analyze such behavior. It will allow to better alloy compositions aimed to mitigate degradation and to design alloys showing stable performance of fuel cell

Colouring titanium alloys by anodic oxidation

The present study is focused on analyzing the change of colors of anodized titanium and effects of applied electrolytic voltages on chromatics. The titanium specimens were anodize in 20 g/L citric acid and 20 g/L baking soda electrolyte by use of different voltages. The colors of anodize titanium were measured with a spectrophotometer and then evaluated in the CIELAB color space. It is found that different volt produces different colors. Anodizing in the range of 15 V to 150 V produces respectively a wide spectrum of color ranging from brown to fuchsia. It can be concluded that the colors of the anodize titanium are dependent upon the applied voltages

Suitability study of Endless Strip Production technology for fabrication of api grades

Production of hot rolled strip for oil and gas transport pipelines requires a fine and homogeneousmicrostructure and careful choice of chemical composition in order to meet strength, toughness, andweldability requirements. Whilst hot rolled coils to grade X80, produced by conventional continuous castingand hot rolling, are a commercial reality, there is great interest in producing API grades manufactured by thealternative (and more economical) thin slab direct rolling route.The current work has assessed the feasibility of producing hot rolled strip of grades X65-X70 using the endlessstrip production layout (ESP), originally developed at Arvedi. The study was carried out using a metallurgicalmodelling system based on empirical equations describing austenite evolution, transformation and mechanicalproperties. Using this approach it was possible to study the effects of initial slab thickness, reduction ratio andchemical composition on the mechanical properties of strips in a thickness range of 10 to 20 mm. In this way,for each grade, the optimum rolling schedules, microstructures and chemical compositions could be obtained

Interrupted quenching in high carbon steels for forgings

The present study is focused on analyzing the effect of the interrupted quenching followed by a partitioning process in a high carbon steel 0,50 % C, 1,50 % Mn, 0,40 % Si, 2,00 % Cr without significant contribution of Al. Thermal treatments were performed at laboratory scale in a quenching dilatometer Linseis R.I.T.A RL78. The fractions of retained austenite were evaluated by scanning electron microscope. The temperature for the interrupted quenching phase was evaluated based on the Koistenen and Marburger equation (adapted to the 0,50 % C steel) and the result highlights a correlation between the chosen different temperature of quenching and the fraction of retained austenite formed during the quenching step of the process

Analisi del processo di deformazione a caldo e dell’evoluzione microstrutturale di un acciaio al 3% Cr mediante prove di torsione

Lo studio dell’evoluzione della microstruttura durante il processo di deformazione plastica di acciai rivestefondamentale importanza. In questo lavoro è stato analizzato il comportamento a deformazione a caldo di unacciaio 3% Cr tramite prove di torsione eseguite nell’intervallo di temperatura 1000?1200°C e con e.compresatra 0.01 e 1.00s-1. L’analisi condotta ha consentito di determinare le costanti della legge di potenza che regolail processo di deformazione a caldo (A0 , Q ed n ) tramite le quali è possibile ottimizzare i processi industriali.L’evoluzione microstrutturale durante la deformazione a caldo è stata valutata in termini di grado di percentualedi fase ricristallizzata ed è analizzata attraverso microscopia elettronica a trasmissione (TEM) e microscopiaad orientazione di immagine-diffrazione da retrodiffusione elettronica (OIM?EBSD). In particolare attraversoquesta ultima tecnica viene stimata la frazione volumetrica di ricristallizzato in termini di parametro GOS (GrainOrientation Spread), che meglio sembra interpretare l’evoluzione microstrutturale dopo deformazione a caldo inmicrostrutture martensitiche

Long-term effectiveness of benralizumab in severe eosinophilic asthma patients treated for 96-weeks: data from the ANANKE study

Background: The efficacy of benralizumab has been broadly demonstrated in severe eosinophilic asthma (SEA), but only few real-life studies evaluated its long-term effects. Here we present novel data from the ANANKE study in which a large cohort of SEA patients was treated for up to 96 weeks. Methods: ANANKE (NCT04272463) is an observational retrospective Italian study investigating the key characteristics of SEA patients (collected during the 12 months prior to benralizumab initiation) and the clinical outcomes during benralizumab treatment (annual exacerbation rate [AER], lung function, asthma control, OCS use, healthcare resource utilization). A post hoc analysis was also conducted in groups of patients based on history of previous biologic therapy (bio-experienced versus naïve patients). Analyses were descriptive only. Results: Before benralizumab initiation, evaluable SEA patients (N = 162, 61.1% females, mean age 56.0 ± 12.7) showed a median blood eosinophil count (BEC) of 600 cells/mm3 (IQR: 430–890). Patients experienced frequent exacerbations (annualized exacerbation rate [AER]: 4.10, severe AER: 0.98), with impaired lung function and poor asthma control (median ACT score: 14) despite 25.3% reported oral corticosteroid (OCS) use. Nasal polyposis was present in 53.1% patients; 47.5% patients were atopic. After 96 weeks since the start of benralizumab, nearly 90% patients were still on treatment; benralizumab dramatically decreased exacerbations (AER: − 94.9%; severe AER: − 96.9%), improved respiratory parameters (median increase in pre-bronchodilator forced expiratory volume [pre-BD FEV1]: + 400 mL) and asthma control (median ACT score: 23) while eliminating OCS in 60% patients. Importantly, benralizumab effects were either maintained or progressively improved over time, accompanied by a nearly complete depletion of BEC. Benralizumab reduced AER both in naïve (any AER: − 95.9%; severe AER: − 97.5%) and bio-experienced patients (any AER: − 92.4%; severe AER: − 94.0%). Conclusions: Profound and sustained improvements in all asthma outcomes were observed with benralizumab. The correct identification of patients’ eosinophilic-driven asthma phenotype was essential to ensure the achievement of such remarkable results. Trial registration: ClinicalTrials.gov Identifier: NCT04272463