Nanostructural Engineering of Steel

The concept of microstructural engineering of steels is well established and is the basis for a wide range of processes and products. Recently, though, there has been increasing emphasis in developing microstructures that have submicron length scales and also in understanding in far greater detail the structures and solute effects that are occurring at the nanoscale. In this review it is proposed that we are heading towards the situation where we are applying nanostructural engineering concepts in the development of new steels. A range of examples are given as well as a discussion of the potential impact of new processing routes. Clearly the future advances will be driven through improved characterization methods, such as atom probe tomography, in combination with advanced modeling

A study of the strengthening mechanism in the thermomechanically processed TRIP/TWIP steel

The strengthening mechanism responsible for the unique combination of ultimate tensile strength and elongation in a multiphase Fe-0.2C-1.5Mn-1.2Si-0.3Mo-0.6Al-0.02Nb (wt%) steel was studied. The microstructures with different volume fraction of polygonal fenite, bainite and retained austenite were simulated by controlled thermomechanical processing. The interupted tensile test was used to study the bainitic ferrite, retained austenite and polygonal ferrite behavior as a function of plastic strain. X-ray analysis was used to characterize the volume fraction and carbon content of retained austenite. TEM and heat-tinting were utilized to analyze the effect of bainitic fenite morphology on the strain induced transformation of retained austenite and retained austenite twinning as a function of strain in the bulk material. The study has shown that the austenite twinning mechanism is more preferable than the transformation induced plasticity mechanism during the early stages of deformation for a microstructure containing I5% polygonal ferrite, while the transformation induced plasticity effect is the main mechanism in when there is 50% of polygonal ferrite in the microstructure. The baillitic fenite morphology affects the deformation mode of retained austenite during straining. The polygonal fenite behavior during straining depends on dislocation substructure tonned due to the deformation and the additional mobile dislocations caused by the TRIP effect. TRIP and TWIP effects depend not only on the chemical and mechanical stability of retained austenite, but also on the interaction of the phases during straining.<br /

The effect of Nb, Mo, and A1 additions on the transformation behaviour and mechanical properties of thermomechanically processed C-Si-Mn trip steel

The effect of additions of Nb, A1 and Mo to Fe-C-Mn-Si TRIP steels on the final microstructure and mechanical properties after simulated thermomechanical processing (TMP) has been studied. Laboratory simulations of continuous cooling during TMP were performed using a quench deformation dilatometer, while laboratory simulations of discontinuous cooling during TMP were performed using a hot rolling mill. From this a comprehensive understanding of the structural and kinetic aspects of the bainite transformation in these types of TRIP steels has been developed. All samples were characterised using optical microscopy and XRD. The relationships between the morphology of bainitic structure, volume fraction, stability of RA and mechanical properties were investigated.<br /

Uloga dodataka Cr i P u razvoju mikrostrukture i teksture u žarenim niskougljičnim čelicima

The recrystallisation behaviour of four warm rolled steels was investigated during annealing. The extra-low carbon (ELC) steel displayed the highest rate of recrystallisation, the steels with additions of chromium and phosphorus (LC(Cr)), (LC(Cr,P)) recrystallised at intermediate rates, while the interstitial-free (IF) steel exhibited the lowest rate. The additions of Cr and Cr/P increased the fraction of g-fibre in the annealing textures compared to that present in the ELC steel; this effect was particularly pronounced up to 50 % recrystallisation. After the completion of recrystallisation, the steel textures were characterized by a dominant g-fibre in the IF steel, while in the three LC steels, the RD fibre was the principal one.Ispitivana je rekristalizacija četiri tipa toplo valjanih čelika tijekom žarenja. Čelik s ekstra niskim ugljikom (ELC) pokazao je najveću brzinu rekristalizacije, čelici s dodatkom kroma i fosfora (LC(Cr)), (LC(Cr,P)) pokazali su srednje brzine rekristalizacije, dok je intersticijski-slobodan čelik (IF) imao najmanju brzinu. Dodavanje Cr i Cr/P povećalo je frakciju -vlaknastog materijala u žarenim teksturama u usporedbi s onom koju susrećemo u ELC čeliku; taj efekt je posebno izražen u 50 %-postotnoj rekristalizaciji. Nakon završetka rekristalizacije, teksture čelika su obilježene dominacijom -vlaknastog tkiva u IF-čeliku, dok je u tri LC čelika RD-vlakno bilo glavno

Ценностные установки представителей разных поколений в процессе принятия решений о выборе вуза и образовательной программы

Purpose: is to propose the methodological approach to modeling the behavior of the representatives of generations Y and Z in the process of making decisions about choosing a university and educational program based on differences in their value systems.Methods: the theoretical and methodological basis for studying the value systems of potential and actual university students is the theory of generations. The findings of the study are based on the methods of analysis of secondary and primary data collected through an online survey of students belonging to generations Y and Z on representative samples of 380 (Y) and 788 (Z) observations in 20 large universities in Russia, as well as the methods of analysis of statistically significant differences in value systems of two generations using T-test for independent samples.Results: the authors proposed the methodological approach to modeling the behavior of consumers of generations Y and Z in the process of making decisions on choosing a university and educational program. Based on the results of desk and field (empirical) research, at each stage of the decision-making process on selecting an educational institution and program, differences were identified in the value systems of students of generations Y and Z, which determine their behavior: statistically significant differences were identified in 19 out of 65 variables. The study provides description of the behavior patterns of students of the two generations at each stage of the decision-making process which formed the basis for dividing students into target groups. The guidelines for differentiating marketing interactions with target groups of representatives of two generations in the process of educational interactions while making decisions are proposed.Conclusions and Relevance: differences in the value systems of representatives of generations Y and Z cause differences in behavioral patterns at each stage of the decision-making process. Understanding these differences enables us to model the behavior of the two target groups, differentiate marketing approaches to interaction with them at the stages of the decision-making process while choosing a university and educational program as well as increase the effectiveness of educational interactions in the process of education.Цель. Предложить методический подход к моделированию поведения представителей поколений Y и Z при принятии решений о выборе вуза и образовательной программы на основе различий в их ценностных установках.Методы. Теоретико-методической основой изучения ценностных установок потенциальных и фактических студентов вузов является теория поколений. Выводы исследования основаны на методах анализа вторичных, а также первичных данных онлайн-опроса студентов, относящихся к поколениям Y и Z, на репрезентативных выборках объемами 380 (Y) и 788 (Z) наблюдений в 20-ти крупных вузах России, методах анализа статистически значимых различий в ценностных установках двух поколений посредством метода Т-критерия для независимых выборок.Результаты работы. Авторами предложен методический подход к моделированию поведения представителей поколений Y и Z в процессе принятия решений о выборе вуза и образовательной программы. По результатам кабинетного и полевого (эмпирического) исследований на каждом этапе процесса принятия решений выявлены различия в ценностных установках студентов поколений Y и Z, определяющие их поведение: из 65-ти переменных по 19-ти выявлены статистически значимые различия. Описаны модели поведения студентов двух поколений на каждом этапе процесса принятия решений, которые легли в основу деления обучающихся на целевые группы. Предложены направления по дифференциации маркетинговых интеракций с целевыми группами представителей двух поколений в процессе образовательного взаимодействия при принятии ими решений.Выводы. Различия в ценностных установках представителей поколений Y и Z обусловливают различия в поведенческих паттернах на каждом этапе процесса принятия решений. Понимание этих различий позволяет моделировать поведение двух целевых сегментов, дифференцировать подходы к взаимодействию с ними на этапах процесса принятия решений при выборе вуза и образовательной программы, а также повышать эффективность образовательного взаимодействия в период обучения

Effect of deformation schedule on the microstructure and mechanical properties of a thermomechanically processed C-Mn-Si transformation-induced plasticity steel

Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties of TRIP steel were revealed. The bainite morphology had a more pronounced effect on the mechanical behavior than the refinement of the microstructure. The improvement of the mechanical properties of TRIP steel was achieved by variation of the volume fraction of the retained austenite rather than the overall refinement of the microstructure. <br /

Управление потребительским опытом на рынке востребованных в кризис финансовых услуг

Purpose: to provide differentiated marketing solutions for manage customer experience based on various demographics, behavioral characteristics and customer values in the process of servicing for investing in gold.Methods: the current study was based upon general scientific methods of analysis and synthesis, applied methods of marketing research. The field market research and analysis of customer experience were carried out in relation to investment opportunities available in banks: physical gold and depersonalized metal accounts. A qualitative research method included “Mystery shopper” – a covert participant observation research of 8 banks in Moscow – the major players offering services for investing in gold.Results: the authors found out that investing in gold becomes in demand during the crisis time. Gold, as an investment opportunity, is a protective asset and retains its value in a long term. The target segments potentially interested in investing in gold can be determined by demographic and behavioral characteristics, desired benefits and values. The authors analyzed the customer experience journey of two segments in the process of investing in through different banking channels. The customer experience was illustrated with customer experience maps that propose management solutions for banks that desire to offer gold investment services.Conclusions and Relevance: in the context of geopolitical and economic instability, the demand for investment opportunities in gold remains high. While customers value high level of services and investment appeal banks are interested in obtaining a stable income. To provide a mutually beneficial cooperation it is important to create a level of service that would fully meet consumer demand. The basis to create a high-quality service for investing in gold include specific management strategies enabling to receive omnichannel (both digital and non-digital) customer experience in various customer segments.Цель работы – представить дифференцированные маркетинговые решения по управлению опытом конечных потребителей с различными демографическими и поведенческими характеристиками и ценностями при продаже услуг по инвестированию в золото.Методы: Для выполнения задач исследования были использованы общенаучные методы анализа и синтеза, прикладные методы маркетинговых исследований. Полевое исследование и анализ потребительского опыта проведены в отношении объектов инвестирования, доступных в банках: физическое золото и обезличенные металлические счета. Применен качественный метод исследования «тайный покупатель»: скрытое включенное наблюдение за моделями продаж 8-ми банков г. Москвы – крупнейших игроков, предлагающих услуги по инвестированию в золото.Результаты работы. Авторами показано, что одной из финансовых услуг, востребованных в кризис, является инвестирование в золото. В процессе исследования были определены потенциальные целевые потребительские сегменты, готовые инвестировать в золото через различные инструменты, доступные в банках. Целевые сегменты отличаются демографическими и поведенческими характеристиками, искомыми выгодами, ценностями. Проанализирован клиентский путь целевых сегментов потребителей при инвестировании в золото в разных каналах банковского обслуживания. Предложены дифференцированные решения по управлению потребительским опытом потребителей целевых сегментов при продаже услуг инвестирования в золото, иллюстрированные картами потребительского опыта.Выводы. В условиях геополитической и экономической нестабильности интерес со стороны частных инвесторов к услуге инвестирования в золото остается высоким. Для взаимовыгодного обмена ценностями в данных условиях, получения потребителями искомых ценностей и стабильного дохода банками, важно создать такое предложение, качество и количество которого будут соответствовать потребительскому спросу. Основой создания качественного предложения услуг по инвестированию в золото являются дифференцированные стратегии управления потребительским опытом целевых сегментов в цифровых и нецифровых каналах сбыта и коммуникаций, базирующиеся на принципах омниканальности коммуникаций и сбыта

Методика оценки транспортной доступности капитальных объектов мегаполиса на основе геоинформационных данных

Purpose: to present the author's methodology and the test results for calculating integral indicators of transport accessibility on the basis of weighted normalized private indicators for three housing estates in Moscow.Methods: the study is based on the application of methods for collecting factual material, its processing, systematic, comparative historical and structural-functional analysis, which were supplemented by multivariate analysis of secondary information using content analysis of existing methods for calculating indicators of transport accessibility of capital objects. The results and conclusions of the research are based on the use of the author's methodology for calculating integral indicators of transport accessibility based on weighted normalized private indicators for three housing estates in Moscow. The analysis of a possible set of criteria for assessing transport accessibility of housing estates in Moscow metropolis was carried out on the basis of the use of a geographic information system database GIS NextGIS QGIS.Results: a review of methodological approaches to the calculation of objective quantitative indicators characterizing the transport accessibility of capital objects is carried out; the author's methodology for calculating the integral indicators of the transport accessibility of residential complexes in Moscow is presented and tested on the basis of weighted normalized private criteria / indicators. The use of the authors’ methodology for calculating integral indicators of transport accessibility based on weighted normalized private criteria / indicators made it possible to calculate the values of indicators of transport accessibility for three housing estates in Moscow, calculate an integrated score for a set of transport accessibility criteria for each housing estate, to give a comparative quantitative assessment of their transport accessibility, to conduct a rating of housing estates in terms of their transport accessibility.Conclusions and Relevance: the presented results of approbation of the author's methodology for calculating the integral indicators of transport accessibility for housing estates in Moscow allow to conduct a comparative and dynamic analysis of housing estates (or larger units) transport accessibility. The results of such an analysis can be applied in order to develop programs for transport infrastructure development of the megacity as a whole, its certain districts and city parts, as well as to assess such programs efciency. The authors see the directions for future research in the defnition and calculation of indicators based on the city dwellers perception of the transport accessibilityЦель: представить авторскую методику по расчету интегральных показателей транспортной доступности на основе взвешенных нормированных частных показателей и результаты ее апробации для трех жилых комплексов г. Москвы.Метод или методология проведения работы. Исследование основано на применении методов сбора фактического материала, его обработки, системного, сравнительно-исторического и структурно-функционального анализа, которые были дополнены многомерным анализом вторичной информации с использованием контент-анализа существующих методик расчета показателей транспортной доступности капитальных объектов. Результаты и выводы работы базируются на использовании авторской методики расчета интегральных показателей транспортной доступности на основе взвешенных нормированных частных показателей для трех жилых комплексов г. Москвы. Анализ возможной совокупности критериев/показателей оценки транспортной доступности жилищных комплексов мегаполиса г. Москва был проведен на основе использования геоинформационной базы данных ГИС NextGIS QGIS.Результаты работы. Проведен обзор методических подходов к расчету объективных количественных показателей, характеризующих транспортную доступность капитальных объектов, представлена и апробирована авторская методика расчета интегральных показателей транспортной доступности жилых комплексов г. Москвы на основе взвешенных нормированных частных критериев/показателей. Применение авторской методики расчета интегральных показателей транспортной доступности на основе взвешенных нормированных частных критериев/показателей позволило рассчитать значения показателей транспортной доступности для трех жилых комплексов г. Москвы, рассчитать интегрированную балльную оценку совокупности критериев транспортной доступности для каждого ЖК, дать сравнительную количественную оценку их транспортной доступности, провести рейтингование ЖК по показателям транспортной доступности.Выводы. Представленные результаты апробации авторской методики расчета интегральных показателей транспортной доступности для жилых комплексов г. Москвы позволяют проводить сравнительный и динамический анализ транспортной доступности ЖК (или более крупных агрегатов). Результаты такого анализа могут быть применены в целях разработки программ развития транспортной инфраструктуры мегаполиса в целом, отдельных округов и районов, а также для оценки эффективности таких программ. В целях дальнейшего развития системы оценки транспортной доступности авторы видят направления будущих исследований в определении и расчете показателей, основанных на восприятии жителями города транспортной доступности объектов

Strengthening mechanisms in thermomechanically processed NbTi-microalloyed steel

The effect of deformation temperature on microstructure and mechanical properties was investigated for thermomechanically processed NbTi-microalloyed steel with ferrite-pearlite microstructure. With a decrease in the finish deformation temperature at 1348 K to 1098 K (1075 °C to 825 °C) temperature range, the ambient temperature yield stress did not vary significantly, work hardening rate decreased, ultimate tensile strength decreased, and elongation to failure increased. These variations in mechanical properties were correlated to the variations in microstructural parameters (such as ferrite grain size, solid solution concentrations, precipitate number density and dislocation density). Calculations based on the measured microstructural parameters suggested the grain refinement, solid solution strengthening, precipitation strengthening, and work hardening contributed up to 32 pct, up to 48 pct, up to 25 pct, and less than 3 pct to the yield stress, respectively. With a decrease in the finish deformation temperature, both the grain size strengthening and solid solution strengthening increased, the precipitation strengthening decreased, and the work hardening contribution did not vary significantly

Effect of microstructure on the stability of retained austenite in transformation-induced-plasticity steels

Two Fe-0.2C-1.55Mn-1.5Si (in wt pet) steels, with and without the addition of 0.039Nb (in wt pet), were studied using laboratory rolling-mill simulations of controlled thermomechanical processing. The microstructures of all samples were characterized by optical metallography, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The microstructural behavior of phases under applied strain was studied using a heat-tinting technique. Despite the similarity in the microstructures of the two steels (equal amounts of polygonal ferrite, carbide-free bainite, and retained austenite), the mechanical properties were different. The mechanical properties of these transformation-induced-plasticity (TRIP) steels depended not only on the individual behavior of all these phases, but also on the interaction between the phases during deformation. The polygonal ferrite and bainite of the C-Mn-Si steel contributed to the elongation more than these phases in the C-Mn-Si-Nb-steel. The stability of retained austenite depends on its location within the microstructure, the morphology of the bainite, and its interaction with other phases during straining. Granular bainite was the bainite morphology that provided the optimum stability of the retained austenite.<br /