Design, manufacturing and performance OF Fe–Mn–Si–Ni–Cr shape memory seamless couplings

The Fe–Mn–Si shape memory (SM) alloys have attracted a great deal of interest due to their good technological characteristics and mechanical properties, combined with the SM effect. They are especially useful for applications like shaft and pipe couplings. In this work, we present the development and evaluation of a procedure to manufacture SM seamless couplings. After analysing industrial forming methods, we designed and fabricated a prototype of a punch-extrusion (PE) die and obtained seamless tubes of satisfactory quality and length for manufacturing couplings. Finally, we measured the performance and SM properties of the PE couplings and compared these characteristics to those of couplings machined from a cast ingot. We concluded that a multi-step processing is an efficient solution that mitigated problems resulting from billet cooling during punching because it allows the alloy to be reheated. The PE couplings that were diametrically expanded 4% and annealed at 700 °C exhibited 75% shape recovery, while the control samples showed 20% less recovery. The union of 21 mm diameter shafts by means of PE couplings annealed at 700 °C showed 40 N-m/cm2 normalized torque transmission, which was 25% greater than that found for the cast ingot couplings. We also analyzed the advantages of the PE couplings compared to a traditional shrink-fit connection.Fil: Esquivel, Isidro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Malarria, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Druker, Ana Velia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentin

Оглавление. Инновационные технологии в металлургии и машиностроении

Представлены материалы фундаментальных аспектов физики и механики большой пластической деформации; физических основ и моделей повышения прочности и вязкости разрушения, способов управления структурой и свойствами сталей и сплавов; феноменологических моделей деформируемых сред с изменяющейся дислокационной и зеренной структурой; механики вязкого разрушения сталей и сплавов при большой пластической деформации; научных основ технологических процессов восстановления металлургической продукции, отслужившей первоначальный эксплуатационный ресурс; конечно-элементного моделирования и оптимизации технологических процессов и комплексов; модернизации технологии производства листа, сортовых профилей проката, труб, метизов, полуфабрикатов и штампованных поковок, а также продукции для энергетического и транспортного машиностроения

Strain-Based Design Methodology of Large Diameter Grade X80 Linepipe

Continuous growth in energy demand is driving oil and natural gas production to areas that are often located far from major markets where the terrain is prone to earthquakes, landslides, and other types of ground motion. Transmission pipelines that cross this type of terrain can experience large longitudinal strains and plastic circumferential elongation as the pipeline experiences alignment changes resulting from differential ground movement. Such displacements can potentially impact pipeline safety by adversely affecting structural capacity and leak tight integrity of the linepipe steel. Planning for new long-distance transmission pipelines usually involves consideration of higher strength linepipe steels because their use allows pipeline operators to reduce the overall cost of pipeline construction and increase pipeline throughput by increasing the operating pressure. The design trend for new pipelines in areas prone to ground movement has evolved over the last 10 years from a stress-based design approach to a strain-based design (SBD) approach to further realize the cost benefits from using higher strength linepipe steels. This report presents an overview of SBD for pipelines subjected to large longitudinal strain and high internal pressure with emphasis on the tensile strain capacity of high-strength microalloyed linepipe steel. The technical basis for this report involved engineering analysis and examination of the mechanical behavior of Grade X80 linepipe steel in both the longitudinal and circumferential directions. Testing was conducted to assess effects on material processing including as-rolled, expanded, and heat‑treatment processing intended to simulate coating application. Elastic-plastic and low-cycle fatigue analyses were also performed with varying internal pressures. Proposed SBD models discussed in this report are based on classical plasticity theory and account for material anisotropy, triaxial strain, and microstructural damage effects developed from test data. The study results are intended to enhance SBD and analysis methods for producing safe and cost effective pipelines capable of accommodating large plastic strains in seismically active arctic areas

Book of abstracts of the 16th International Symposium of Croatian Metallurgical Society - SHMD \u272023, Materials and metallurgy

Book of abstracts of the 16th International Symposium of Croatian Metallurgical Society - SHMD \u272023, Materials and metallurgy, Zagreb, Croatia, April 20-21, 2023. Abstracts are organized into five sections: Anniversaries of Croatian Metallurgy, Materials - Section A; Process Metallurgy - Section B; Plastic Processing - Section C and Metallurgy and Related Topics - Section D

Computational simulation of pass rolling

Táto diplomová práca sa zaoberá možnosťami výpočtového modelovania valcovania v kalibroch pomocou metódy konečných prvkov. Na začiatku je formulovaná motivácia pre písanie práce a problémová situácia, nasledovaná zostavením systému podstatných veličín. Ďaľšia kapitola popisuje rôzne spôsoby valcovania ako aj samotný valcovací proces. Dôraz je kladený na popis tradičného návrhu kalibrov. Nasledujúca kapitola sa zaoberá teóriou plasticity, plastickým chovaním materiálu a jeho modelovaním v konečnoprvkovom prostredí Abaqus, ktoré je použité vo výpočtovej časti práce. Predstavené sú viaceré modely plasticity, ako aj modely tvárneho porušovania, používané na posúdenie tvárniteľnosti či simuláciu šírenia tvárnej trhliny v materiáli. Práca pokračuje kapitolou zameranou na metódu konečných prvkov, najmä jej explicitný algoritmus, využívaný vo výpočtovej časti práce. Ďaľšia časť je venovaná popisu základných princípov fotoelasticimetrie, tradičnej experimentálnej metódy. Tieto kapitoly zahŕňajú aj popis konečnoprvkovej a experimentálnej fotoplastickej analýzy konkrétneho prípadu valcovania v kalibroch, riešené v predchádzajúcom článku. Použitý výpočtový model je základom nového konečnoprvkového modelu, ktorého tvorbe je predmetom nasledujúcej kapitoly. Naviac sú vytvorené aj dve varianty pôvodného, zjednodušeného výpočtového modelu. S použitím vytvorených výpočtových modelov sú vykonané štrukturálne analýzy a vyhodnotené viaceré výsledky, následne zhrnuté a porovnané s pôvodnými výpočtovými a experimentálnymi výsledkami. Rozbor porovnania výsledkov a zhodnotenie použiteľnosti a spoľahlivosti jednotlivých výpočtových modelov tvoria záver práce.This master's thesis reviews possibilities of finite element modelling of pass rolling. Motivation and problem formulation may be found at the beginning of the thesis, followed by definition of system of essential variables. Next chapter describes various methods of rolling as well as the rolling process itself. An emphasis is put mainly on pass roll design. The following part deals with material behavior and its modelling in finite element software Abaqus, which is used in the computational part of the thesis. Multiple models of plasticity are introduced here, as well as damage criteria, used to assess material formability or simulate propagation of ductile damage through the material. Next part is focused on finite element method, specifically its explicit algorithm, later employed in the computational part of the thesis. In the last theoretical chapter, basic principles of photoelasticimetry, a traditional experimental method, are described. These chapters also contain description of simplified finite element analysis and photoplastic experimental analysis of a specific pass rolling problem. Computational model used there served as a basis for the new finite element model, creation of which is the purpose of the following chapter. Two variants of the simplified, previously used computational model were recreated as well. Structural analyses were carried out using the three created models and various results were evaluated. Summary of obtained results and their comparison to original computational and experimental results follows. Discussion of the results and evaluation of usability and reliability of individual computational models form conclusion of the thesis.