MODELLING PLASTIC DEFORMATION OF STAINLESS STEEL PIPES

Plastic deformation is the most common technique adopted to manufacture complex shape pieces in the most efficient way. Even higher requirements need to be faced in the different applications. In order to target such requirement quality and compliance tests are carried out aimed to guarantee that these standards are faced; this often means a waste of material and economic resources. A far as concerns welded stainless steel pipes many criticises affecting the general trend of subsequent machining need to be considered. In this paper the effects of different process parameters and geometrical constrains on austenitic stainless steel pipe forming are studied by Finite Elements Method (FEM) simulations. The model sensitivity to input parameters is reported. The feasibility of the simulated process is evaluated through the use of Forming Limit Diagrams (FLD). </p

effect of thermo mechanical processes on microstructure evolution in austenitic stainless steels

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Analysis of Forming Parameters Involved in Plastic Deformation of 441 Ferritic Stainless Steel Tubes

A welded stainless steel tube is a component used in several industrial applications. Its manufacturing process needs to follow specific requirements based on reference standards. This calls for a predictive analysis able to face some critical issues affecting the forming process. In this paper, a model was adopted taking into account the tube geometrical parameters that was able to describe the deformation process and define the best industrial practices. In this paper, the effect of different process parameters and geometric constraints on ferritic stainless steel pipe deformation is studied by finite element method (FEM) simulations. The model sensitivity to the input parameters is reported in terms of stress and tube thinning. The feasibility of the simulated process is assessed through the comparison of Forming Limit Diagrams. The comparison between the calculated and experimental results proved this approach to be a useful tool in order to predict and properly design industrial deformation processes

tribological properties of wear resistant coatings obtained by cold gas dynamic spray

Abstract The aim of this study was obtaining good deposits of stellite-6 by Cold Gas Dynamic Spray (CGDS), in terms of low porosity and good adhesion and cohesion. In fact, the high strength and melting point of the investigated alloy lead to a high value of the particle critical velocity in CGDS and, therefore, good quality results are difficult to achieve. The tribological properties of the coatings were analyzed by micro-hardness measurements and pin-on-disk wear tests. Results revealed that spraying parameters can be optimized to obtain almost pore-free coatings

Austenitic stainless steels manufacturing by laser powder bed fusion technique

In this paper we report about the possibility to process stainless steels by laser powder bed fusion (L-PBF) systems. Austenitic stainless steels are analysed showing the possibility to successfully process them, targeting different applications. In particular, it is shown that stainless steels can be successfully processed and their mechanical behaviour allow them to be put in service. Porosities inside manufactured components are extremely low and comparable to conventionally processed materials. Mechanical performances are even higher than standard requirements. Micro surface roughness typical of the as-built material can act as crack initiator, reducing the strength in both quasi-static and dynamic conditions

Analysis of plastic forming parameters in AISI 441 stainless steel

Plastic deformation is the most common technique adopted to manufacture complex shape pieces in the most efficient way. Even higher requirements need to be faced in the different applications. In order to target such requirement quality and compliance tests are carried out aimed to guarantee that these standards are faced. This often means a waste of material and economic resources. A far as concerns welded stainless steel pipes many criticises affecting the general trend of subsequent machining need to be considered. Such critical issues are more evident in the case of ferritic stainless steel with respect to austenitic ones. Therefore, the study of operating and geometric parameters is fundamental in the production process of ferritic stainless-steel tubes, whose use is mainly for the automotive industry. The possibility to simulate by finite element method (FEM) allows to evaluate the effect of geometric parameters and process constraints on plastic deformation tubes capability, thus allowing to properly fit the plastic deformation process to the target shape as a function of the adopted steel

Sustained Effectiveness of Benralizumab in Naïve and Biologics-Experienced Severe Eosinophilic Asthma Patients: Results from the ANANKE Study

Purpose: Severe eosinophilic asthma (SEA) patients often present overlapping inflammatory features rendering them eligible for multiple biologic therapies; switching biologic treatment is a strategy adopted to optimize asthma control when patients show partial or no response to previous biologics. Patients and Methods: ANANKE is a retrospective, multicenter Italian study (NCT04272463). Here, we outline the characteristics and long -term clinical outcomes in naive-to-biologics and biologics-experienced patients treated with benralizumab for up to 96 weeks. Bioexperienced patients were split into omalizumab and mepolizumab subsets according to the type of biologic previously used. Results: A total of 124 (76.5%) naive and 38 (23.5%) bio-experienced patients were evaluated at index date; 13 patients (34.2%) switched from mepolizumab, 21 patients (55.3%) switched from omalizumab, and four patients (10.5%) received both biologics. The mepolizumab subset was characterized by the longest SEA duration (median of 4.6 years), the highest prevalence of chronic rhinosinusitis with nasal polyposis (CRSwNP) (76.5%), and the greatest oral corticosteroid (OCS) daily dosage (median of 25 mg prednisone equivalent). The omalizumab group showed the highest severe annual exacerbation rate (AER) (1.70). At 96 weeks, treatment with benralizumab reduced any and severe AER by more than 87% and 94%, respectively, across all groups. Lung function was overall preserved, with major improvements observed in the mepolizumab group, which also revealed a 100% drop of the median OCS dose. Asthma Control Test (ACT) score improved in the naive group while its increment was more variable in bio-experienced patients; among these, a marked difference was noticed between omalizumab and mepolizumab subsets (median ACT score of 23.5 and 18, respectively). Conclusion: Benralizumab promotes durable and profound clinical benefits in naive and bio-experienced groups, indicating that a nearly complete depletion of eosinophils is highly beneficial in the control of SEA, independently of previous biologic use

Benralizumab in Patients With Severe Eosinophilic Asthma With and Without Chronic Rhinosinusitis With Nasal Polyps: An ANANKE Study post-hoc Analysis

Background: Severe eosinophilic asthma (SEA) in the presence of chronic rhinosinusitis with nasal polyps (CRSwNP) indicates the presence of a more extensive eosinophilic inflammation. Post-hoc analyses from a pivotal clinical trial have demonstrated the enhanced efficacy of benralizumab on asthma outcomes in patients with CRSwNP as a comorbidity. Methods: This is a post-hoc analysis from the Italian multi-center observational retrospective ANANKE study. Patients were divided into two groups based on self-reported CRSwNP. Baseline clinical and laboratory features in the 12 months prior to benralizumab prescription were collected. Data of change over time of blood eosinophils, annualized exacerbations rates (AER), asthma control, lung function, oral corticosteroids (OCS) use, and benralizumab discontinuation were collected during the observation period. Results: At baseline, the 110 patients with CRSwNP were less frequently female (50.9% vs 74.2%) and obese (9.1% vs. 22.6%) with higher eosinophils (605 vs. 500 cells/mm3) and OCS use when compared to patients without CRSwNP. Similar reductions of AER were seen (-95.8% vs. -91.5% for any exacerbation and -99.1% vs. -92.2% for severe exacerbations in patients with and without CRSwNP, respectively). During benralizumab treatment, comorbid SEA+CRSwNP was associated with a lower risk of any exacerbation (p = 0.0017) and severe exacerbations (p = 0.025). After a mean +/- SD exposure of 10.3 +/- 5.0 months, half of the SEA+CRSwNP patients eliminated OCS use. No discontinuation for safety reasons was recorded. Conclusions: This study helped to confirm the baseline clinical features that distinguish patients with and without CRSwNP being prescribed benralizumab. Numerically enhanced OCS reduction and lower exacerbation risk were observed in patients with SEA and comorbid CRSwNP treated with benralizumab

Benralizumab in Patients With Severe Eosinophilic Asthma With and Without Chronic Rhinosinusitis With Nasal Polyps: An ANANKE Study post-hoc Analysis

Background: Severe eosinophilic asthma (SEA) in the presence of chronic rhinosinusitis with nasal polyps (CRSwNP) indicates the presence of a more extensive eosinophilic inflammation. Post-hoc analyses from a pivotal clinical trial have demonstrated the enhanced efficacy of benralizumab on asthma outcomes in patients with CRSwNP as a comorbidity. Methods: This is a post-hoc analysis from the Italian multi-center observational retrospective ANANKE study. Patients were divided into two groups based on self-reported CRSwNP. Baseline clinical and laboratory features in the 12 months prior to benralizumab prescription were collected. Data of change over time of blood eosinophils, annualized exacerbations rates (AER), asthma control, lung function, oral corticosteroids (OCS) use, and benralizumab discontinuation were collected during the observation period. Results: At baseline, the 110 patients with CRSwNP were less frequently female (50.9% vs 74.2%) and obese (9.1% vs. 22.6%) with higher eosinophils (605 vs. 500 cells/mm3) and OCS use when compared to patients without CRSwNP. Similar reductions of AER were seen (-95.8% vs. -91.5% for any exacerbation and -99.1% vs. -92.2% for severe exacerbations in patients with and without CRSwNP, respectively). During benralizumab treatment, comorbid SEA+CRSwNP was associated with a lower risk of any exacerbation (p = 0.0017) and severe exacerbations (p = 0.025). After a mean ± SD exposure of 10.3 ± 5.0 months, half of the SEA+CRSwNP patients eliminated OCS use. No discontinuation for safety reasons was recorded. Conclusions: This study helped to confirm the baseline clinical features that distinguish patients with and without CRSwNP being prescribed benralizumab. Numerically enhanced OCS reduction and lower exacerbation risk were observed in patients with SEA and comorbid CRSwNP treated with benralizumab

ChAracterization of ItaliaN severe uncontrolled Asthmatic patieNts Key features when receiving Benralizumab in a real-life setting: the observational rEtrospective ANANKE study

Background: Data from phase 3 trials have demonstrated the efficacy and safety of benralizumab in patients with severe eosinophilic asthma (SEA). We conducted a real-world study examining the baseline characteristics of a large SEA population treated with benralizumab in clinical practice and assessed therapy effectiveness. Methods: ANANKE is an Italian multi-center, retrospective cohort study including consecutive SEA patients who had started benralizumab therapy ≥ 3&nbsp;months before enrolment (between December 2019 and July 2020), in a real-world setting. Data collection covered (1) key patient features at baseline, including blood eosinophil count (BEC), number and severity of exacerbations and oral corticosteroid (OCS) use; (2) clinical outcomes during benralizumab therapy. We also conducted two post-hoc analyses in patients grouped by body mass index and allergic status. Analyses were descriptive only. Results: Of 218 patients with SEA enrolled in 21 Centers, 205 were evaluable (mean age, 55.8 ± 13.3&nbsp;years, 61.5% females). At treatment start, the median BEC was 580 cells/mm3 (interquartile range [IQR]: 400-850); all patients were on high-dose inhaled controller therapy and 25.9% were on chronic OCS (median dose: 10&nbsp;mg/die prednisone-equivalent [IQR: 5-25]); 92.9% experienced ≥ 1 exacerbation within the past 12&nbsp;months (annualized exacerbation rate [AER] 4.03) and 40.3% reported ≥ 1 severe exacerbation (AER 1.10). During treatment (median duration: 9.8&nbsp;months [IQR 6.1-13.9]; ≥ 12&nbsp;months for 34.2% of patients), complete eosinophil depletion was observed; exacerbation-free patients increased to 81% and only 24.3% reported ≥ 1 severe event. AER decreased markedly to 0.27 for exacerbations of any severity (-&nbsp;93.3%) and to 0.06 for severe exacerbations (-&nbsp;94.5%). OCS therapy was interrupted in 43.2% of cases and the dose reduced by 56% (median: 4.4&nbsp;mg/die prednisone-equivalent [IQR: 0.0-10.0]). Lung function and asthma control also improved. The effectiveness of benralizumab was independent of allergic status and body mass index. Conclusions: We described the set of characteristics of a large cohort of patients with uncontrolled SEA receiving benralizumab in clinical practice, with a dramatic reduction in exacerbations and significant sparing of OCS. These findings support benralizumab as a key phenotype-specific therapeutic strategy that could help physicians in decision-making when prescribing biologics in patients with SEA. Trial registration ClinicalTrials.gov Identifier: NCT04272463