scholarly journals Physical and chemical models for expert evaluation of mechanical properties of structural steels

2018 ◽  
pp. 384-393
Author(s):  
A.A. Kononenko ◽  
A.V. Puchikov ◽  
O.V. Kuksa ◽  
A.N. Kuksa ◽  
I.R. Snigura
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Control Systems ◽  
Interatomic Interaction ◽  
Structural Steels ◽  
Expert Assessment ◽  
Iron And Steel ◽  
Chemical Models ◽  
Two Samples ◽  
The Matrix

The aim of the study is to develop an adapted methodology for assessing the influence of the chemical composition on the properties of multicomponent steels and finished rolled products. An approach to predicting the mechanical properties of structural steels with regard to heat treatment parameters, based on the concept of a directed chemical bond in the description of interatomic interaction in the melt, is presented. The physico-chemical models of the structure of the melts, which interconnect their composition, structure, and properties, were developed in the Iron and Steel Institute of NAS Ukraine. The representation of the element-by-element composition of multicomponent steels in the integral parameters of the interatomic interaction makes it possible to reduce the parametricity of the models. The role of various pairing interactions of alloying, microalloying and impurity elements in the formation of properties of steels and alloys was evaluated. A factor analysis has been carried out, the chemical composition of the steel has been structured into various subsystems. It is shown that the most significant subsystems are the matrix m (C, Si, Mn) and microalloying ml (Cr, Mo, V, Ni, Ti, Nb). For two samples of structural steels with significant technological differences and features (1-st group - low alloyed steels: St3sp, VSt3sp, VMSt3sp; 2-nd group: 09Г2ФБ, 10ХСНД, 15ХСНД, 14Г2САФ, 14Г2АФ, 16Г2АФ) dependencies of the type are obtained: σВ (σ0,2, δ5) = f (interatomic interaction parameters, Vcool). It is shown that the most important parameters for calculating the σB, σ0.2 and δ5 matrix subsystem m are the integral parameters of the interatomic interaction d and ZY, dm and tgαm, and for the microalloying subsystem ml - ZYml and dml, as well as the cooling rate Vcool for both subsystems. The developed semi-empirical models are recommended for expert assessment of the mechanical properties of structural steels and for use in automated control systems and automated process control systems.

scholarly journals Optimisation of chemical composition of high-strength structural steels for achieving mechanical property requirements

2021 ◽  
Author(s):  
Oleksandr Babachenko ◽  
Hanna Kononenko ◽  
Iryna Snigura ◽  
Nataliya Togobytska
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Chemical Composition ◽  
High Strength ◽  
Interatomic Interaction ◽  
Structural Steels ◽  
Integral Model ◽  
Model Parameters ◽  
National Academy Of Sciences ◽  
Iron And Steel

In addition to thermomechanical treatment, one of the main factors affecting the mechanical properties of steel is the chemical composition. The chemical composition may vary for a special high-strength low-alloy steel to meet certain mechanical property requirements. This work presents an approach, based on the method of physical-chemical modelling developed at the Z.I. Nekrasov Iron and Steel Institute of the National Academy of Sciences of Ukraine, to optimise the chemical composition of high-strength structural steels. The principle of this method is to describe the chemical composition of a melt by a complex of integral model parameters of interatomic interaction, characterising the chemical and structural state of the melt. The experimental data were analysed to obtain the regression model for mechanical properties based on the parameters of interatomic interaction. Finally, a multi-criteria optimisation method was applied to obtain an optimal set of microalloying elements which ensure the required mechanical properties.

scholarly journals The interrelation of the chemical composition and mechanical properties of constructional alloyed steels

2018 ◽  
pp. 328-335
Author(s):  
V.A. Lutsenko ◽  
E.V. Parusov ◽  
T.N. Golubenko ◽  
O.V. Lutsenko ◽  
O.V. Parusov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Chemical Composition ◽  
Relative Elongation ◽  
Interatomic Interaction ◽  
Alloying Elements ◽  
Structural Parameter ◽  
National Academy Of Sciences ◽  
Iron And Steel ◽  
European Standards

The aim of the work is to determine the content intervals of alloying elements in structural alloyed steels, which ensure the obtaining of mechanical properties and the conformity of rolled products to the requirements of European standards. The studies were conducted using a predictive model developed by the Iron and Steel Institute of the National Academy of Sciences of Ukraine, taking into account the full chemical composition of the steel. The regularities of changes in the interatomic interaction parameter on the number of alloying elements in the steel composition and its relationship with mechanical properties are revealed. The dependences of mechanical properties (tensile strength, relative elongation) on the chemical composition of steel are constructed through the physicochemical criterion – the average statistical distance between interacting atoms (structural parameter d). The interrelation between the chemical composition and mechanical properties of chrome-molybdenum structural steels has been established. It is shown that increasing the chromium content increases the tensile strength, and doping with molybdenum and vanadium increases the ductility of rolled products. It was determined that in order to guarantee compliance with the requirements of the ultimate strength (900-1100 MPa) and relative elongation (> 11%) for steel 31CrMoV9, the content of alloying elements should correspond to the following intervals: 2.42-2.62%Cr, 0.2-0, 23%Mo and 0.17-0.20%V. The results obtained make it possible to predict the mechanical properties of doped steel, depending on the actual chemical composition of the steel.

scholarly journals ADI after Austenitising from Intercritical Temperature

2013 ◽  
Vol 13 (1) ◽  
pp. 81-88
Author(s):  
A. Kowalskia ◽  
S. Kluska-Nawarecka ◽  
K. Regulski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fuzzy Logic ◽  
Cast Iron ◽  
Chemical Composition ◽  
Ductile Iron ◽  
Logic Model ◽  
Plastic Properties ◽  
The Matrix ◽  
Different Temperatures

Abstract ADI subjected to austenitising at intercritical temperatures contains in its matrix the precipitates of pre-eutectoid ferrite. Studies were carried out on the ductile iron of the following chemical composition: C = 3,80%, Si = 2,30%, Mn = 0,28%, P = 0,060%, S = 0,010%, Mg = 0,065%, Ni = 0,60%, Cu = 0,70%, Mo = 0,21% This cast iron was austenitised at three different temperatures, i.e. 800, 815 and 830oC and austempered at 360 and 380oC. For each variant of the cast iron heat treatment, the mechanical properties, i.e. YS, TS, EL and Hardness, were measured, and structure of the matrix was examined. Higher plastic properties were obtained owing to the presence of certain amount of pre-eutectoid ferrite. The properties were visualised using fuzzy logic model in a MATLAB. software.

6XXX Alloys: Chemical Composition and Heat Treatment

2019 ◽  
Author(s):  
Grażyna Mrówka-Nowotnik
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Chemical Composition ◽  
Intermetallic Phase ◽  
Chinese Script ◽  
High Dispersion ◽  
Cu Content ◽  
The Matrix ◽  
Si Content ◽  
Additional Phase

Analysis of the influence of chemical composition, crystallization process and heat treatment on the phase constituents’ morphology, and mechanical properties and crack resistance of 6xxx Al alloys were conducted. The alloys with low Mg and Si content (6063) in the as-cast state are characterized by presence of Si particles and primary intermetallic phases: α-Al8Fe2Si, β-Al5FeSi, β-Mg2Si, and α-Al(FeMn)Si. Higher Mg, Si, and Mn content (6005 and 6082) leads to separation of additional phase particles: Al6Fe, Al6Mn, and Al12(FeMn)Mg3Si6, whereas high Cu content (6061—0.35% and 6066—0.95%, respectively) is responsible for precipitation of additional phase particles: Q-Al5Cu2Mg8Si6 and θ-Al2Cu. It has been established that homogenization results in total dissolution of the θ-Al2Cu and Q-Al5Cu2Mg8Si6 primary phases and partial dissolution of β-Mg2Si. Needle-like and Chinese-script α-Al8Fe2Si and β-Al5FeSi were transformed into spheroidal α-Al(FeMn)Si particles. The maximal consolidation of the 6xxx alloys is a result of precipitation of metastable particles, the transient βʺ, βʹ, and Qʹ/θʹ phases (6061 alloy) with high dispersion. The highest mechanical properties were achieved after holding in the temperature of 565°C/6 h, supersaturated in water, and aging at 175°C/10–20 h (T6). The decohesion process in the presence of tensile stresses in the room temperature proceeds through nucleation, the growth and joining of the voids, as well as the cracking of the primary and secondary large-sized intermetallic phase particles. The increase of deformation temperature up to 300°C causes the changes of the nucleation source and joining of voids—it occurs mainly along the matrix–particle interface.

scholarly journals Sintered Structural Steels Containing Mn, Cr And Mo – The Summary of the Investigations

2016 ◽  
Vol 16 (2) ◽  
pp. 59-85
Author(s):  
Maciej Sulowski
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Sintered Material ◽  
Structural Steels ◽  
Processing Conditions ◽  
Alloying Element ◽  
Sintering Atmosphere ◽  
Sintered Steels ◽  
Method Of Production ◽  
Better Than

AbstractThe paper is presented the development and method of production of modern, Ni-free sintered structural steels which contain carbide forming alloying elements (Cr) with high affinity for oxygen (Cr, Mn) and the much smaller additive of an expensive alloying element (Mo), enabling the production of structural sintered steels in commercial belt furnaces, using safe sintering atmospheres. The investigations reported deal with the analysis of microstructure and mechanical properties of these sintered structural steels produced in different processing conditions, especially modification of chemical composition of sintering atmosphere and also the connections between the microstructure of sintered material and its mechanical properties. This analysis was done to propose the appropriate chemical composition of sintered Ni-free steels with properties which are comparable or even better than those of sintered structural steels containing rich and carcinogenic nickel. The investigations of PM Mn- Cr-Mo steels were preceded by those on Mn steels.

scholarly journals Study of Mechanical Properties and Microstructure of Mercedes-Benz and Local Radiator Material

2020 ◽  
Vol 24 (3) ◽  
pp. 185
Author(s):  
Usman Sudjadi ◽  
Rahmad Jayadiningrat ◽  
Erwan Hermawan ◽  
Agus Jamaludin
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Chemical Composition ◽  
Grain Boundaries ◽  
Treatment Process ◽  
Optical Microscope ◽  
Heat Treatment Process ◽  
Test Results ◽  
Binding Material ◽  
The Matrix

            Indonesia has the capability to produced local products such as vehicle radiators. Many studied were carried out to characterize the radiator material. But it still needs to compare local products and imported products. This study carried mechanical properties and microstructure analysis for Marcedes Benz's core radiator and local radiator. The tools used in this study are microhardness tools, optical microscopes, and XRF. The result shows that the Mercedes-Benz radiator binding material before the heat treatment process, using an optical microscope shows the invisible results of a collection of atoms and the matrix and grain boundaries. On local radiator material, Not yet seen the collection of atoms and matrix and grain boundaries. White grains of Mercedes Benz radiator material is more abundant than local radiator materials. Chemical composition test results are; local radiator material content is dominated by three elements Ca (26.3%), Zn (44.4%) and Cu (13.9%) Cu (2.48%), Fe (45.15%), and Mn (44.88%). The German Mercedes-Benz element contents are; Fe (28.7), Mn (27.5), Ca (39.2). The hardness of the Mercedes-Benz radiator before heating is 43.4 HV, after being heated 39.2 HV. The hardness local radiator material before heating 43.5 HV and after heating 38.2 HV.

Structural/Property Relationships for Optical Materials

1993 ◽  
Vol 329 ◽  
Author(s):  
Vivien D.
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Electronic Structure ◽  
Chemical Composition ◽  
Field Strength ◽  
Optical Materials ◽  
Site Occupancy ◽  
Laser Materials ◽  
Crystal Field Strength ◽  
The Matrix

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.

Developing the basis of the matrix model of the regional innovation subsystem

2020 ◽  
Vol 18 (11) ◽  
pp. 2183-2204
Author(s):  
E.I. Moskvitina
Keyword(s):  
Russian Federation ◽  
Matrix Model ◽  
Federal District ◽  
Assessment Method ◽  
Expert Assessment ◽  
Regional Innovation ◽  
Regional Strategies ◽  
Analysis And Synthesis ◽  
The Matrix ◽  
The Russian Federation

Subject. This article deals with the issues related to the formation and implementation of the innovation capacity of the Russian Federation subjects. Objectives. The article aims to develop the organizational and methodological foundations for the formation of a model of the regional innovation subsystem. Methods. For the study, I used the methods of analysis and synthesis, economics and statistics analysis, and the expert assessment method. Results. The article presents a developed basis of the regional innovation subsystem matrix model. It helps determine the relationship between the subjects and the parameters of the regional innovation subsystem. To evaluate the indicators characterizing the selected parameters, the Volga Federal District regions are considered as a case study. The article defines the process of reconciliation of interests between the subjects of regional innovation. Conclusions. The results obtained can be used by regional executive bodies when developing regional strategies for the socio-economic advancement of the Russian Federation subjects.

Study of the character and causes of destruction of the cardan shaft of the propeller engine

2019 ◽  
Vol 85 (12) ◽  
pp. 43-50
Author(s):  
D. A. Movenko ◽  
L. V. Morozova ◽  
S. V. Shurtakov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Yield Point ◽  
Protective Coating ◽  
Fracture Pattern ◽  
Corrosion Cracking ◽  
Tempered Martensite ◽  
Neck Formation ◽  
Static Mechanism ◽  
Shaft Surface

The results of studying operational destruction of a high-loaded cardan shaft of the propeller engine made of steel 38KhN3MFA are presented to elucidate the cause of damage and develop a set of recommendations and measures aimed at elimination of adverse factors. Methods of scanning electron and optical microscopy, as well as X-ray spectral microanalysis are used to determine the mechanical properties, chemical composition, microstructure, and fracture pattern of cardan shaft fragments. It is shown that the mechanical properties and chemical composition of the material correspond to the requirements of the regulatory documentation, defects of metallurgical origin both in the shaft metal and in the fractures are absent. The microstructure of the studied shaft fragments is tempered martensite. Fractographic analysis revealed that the destruction of cardan shaft occurred by a static mechanism. The fracture surface is coated with corrosion products. The revealed cracks developed by the mechanism of corrosion cracking due to violation of the protective coating on the shaft. The results of the study showed that the destruction of the cardan shaft of a propeller engine made of steel 38Kh3MFA occurred due to formation and development of spiral cracks by the mechanism of stress corrosion cracking under loads below the yield point of steel. The reason for «neck» formation upon destruction of the shaft fragment is attributed to the yield point of steel attained during operation. Regular preventive inspections are recommended to assess the safety of the protective coating on the shaft surface to exclude formation and development of corrosion cracks.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

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