Data Mining Methods for Prediction of Multi-Component Al-Si Alloy Properties Based on Cooling Curves

AbstractThe paper concerns the mechanical properties of hypoeutectic Al-Si alloy (silumin) with the addition of Cr, Mo, V and W. Changes in microstructure under the impact of these elements result in a change in the mechanical properties. Crystallization of Al-Si alloys determines grain size reduction, which causes a significant increase in their strength properties. Crystallization subjected to modifications through the influence of alloying additives can be described by the cooling curve run. Statistical relationships between the characteristic values of cooling curves and mechanical properties are investigated with data mining techniques of regression, especially regression trees. Such knowledge could provide an ability of a property prediction on the basis of cooling curves in terms of the benefits of a short time of the curve registration.

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Microstructure and Mechanical Properties of Modern 11%Cr Heat-Resistant Steel Weld Joints

Materials ◽

10.3390/ma14123430 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3430

Author(s):

Grzegorz Golański ◽

Jacek Słania ◽

Marek Sroka ◽

Paweł Wieczorek ◽

Michał Urzynicok ◽

...

Keyword(s):

Mechanical Properties ◽

Welded Joints ◽

Martensitic Steel ◽

Base Material ◽

Hardness Measurement ◽

Power Industry ◽

Strength Properties ◽

Typical Structure ◽

Δ Ferrite ◽

The Impact

In addition to good high-temperature creep resistance and adequate heat resistance, steels for the power industry must have, among other things, good weldability. Weldability of such steels is one of the criteria determining whether or not the material is suitable for applications in the power industry. Therefore, when materials such as martensitic steel Thor 115 (T115) are introduced into the modern power industry, the quality and properties of welded joints must be assessed. The paper presents the results of metallographic and mechanical investigations of T115 martensitic steel welded joints. The analysis was carried out on joints welded with two filler metals: WCrMo91 (No. 1) and EPRI P87 (No. 2). The scope of the investigations included: microstructural investigations carried out using optical, scanning and transmission electron microscopy and mechanical testing, i.e., Vickers microhardness and hardness measurement, static tensile test and impact test. The macro- and microstructural investigations revealed correct structure of the weld, without welding imperfections. The microstructural investigations of joint No. 1 revealed a typical structure of this type of joint, i.e., the martensitic structure with numerous precipitates, while in joint No. 2, the so-called Nernst’s layers and δ-ferrite patches were observed in the weld fusion zone as well as the heat affected zone (HAZ). The mechanical properties of the test joints met the requirements for the base material. A slight influence of the δ-ferrite patch on the strength properties of joint No. 2 was observed, and its negative effect on the impact energy of HAZ was visible.

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Cast Iron Cooling Rate Variation Using Cooling Channels: A Numerical Approach

Journal of Engineering Research and Reports ◽

10.9734/jerr/2021/v20i417292 ◽

2021 ◽

pp. 29-35

Author(s):

Olumide Adewole Towoju

Keyword(s):

Mechanical Properties ◽

Cast Iron ◽

Cooling Rate ◽

Flow Rate ◽

Numerical Approach ◽

Cooling Curve ◽

Rate Variation ◽

Cooling Fluid ◽

Cooling Channels ◽

The Impact

The cooling rate of molten cast iron can make or mar it. The cooling rate plays a significant role in the resulting mechanical properties of cast iron. It determines the grain growth and size. The mechanical properties of cast iron variation along its length are achieved either with the use of different mold materials or by sectioning to ensure varied cooling rates. Mechanical properties can, however, also be varied along its length without any of these adopted methods by the incorporation of cooling channels in the mould. This study seeks to expand the frontier of this concept with the use of different cooling fluids and fluid flow rate, and numerically investigate the impact on the cooling rate of gray cast iron (class 40). The cooling curve for the cast iron was impacted by the use of different cooling fluids with the attainment of the desired mechanical properties with the selection of an appropriate cooling fluid. Also, the flow rate of the cooling fluid has an impact on the cast iron cooling rate.

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Mechanical Properties of Fibre-Metal Composites Connected by Means of Bolt Joints

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.837.296 ◽

2013 ◽

Vol 837 ◽

pp. 296-301

Author(s):

Sławomir Zolkiewski

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Polyester Resin ◽

Steel Plate ◽

Fibrous Composite ◽

Laminate Plate ◽

Strength Properties ◽

Fibre Metal Laminates ◽

Fibre Metal ◽

The Impact

The fibre-metal laminates made of a steel plate and fibreglass laminate plate were tested in the special laboratory stands. Epoxy resin and polyester resin were used as matrix to fabricate the composites. The fibre-metal laminates combine advantages of metals and laminates. These materials have very good force versus displacement characteristics and overall mechanical properties. They are very popular and widely applied in technical systems. They can be put to use in connecting materials made of various fabrics, connecting high number layer laminates and most of all connecting metals and laminates. In this paper there are the results of testing fibrous composite materials connected in bolt joints presented. Composite materials reinforced with fiberglass, carbon and aramid fibers are considered. The impact of number of applied bolts in a joint on strength properties was investigated. The connections by means of eight or sixteen bolts were compared. A major problem of modelling the composites is assuming physical and material parameters of the analyzed elements.

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Assessment of Service Life of HCM12 Steel After 100 000 Hrs of Service

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0173 ◽

2016 ◽

Vol 61 (2) ◽

pp. 1021-1029 ◽

Cited By ~ 1

Author(s):

A. Zieliński ◽

H. Paszkowska ◽

P. Skupień ◽

G. Golański

Keyword(s):

Mechanical Properties ◽

Creep Resistance ◽

Residual Life ◽

Strength Properties ◽

Steam Superheater ◽

Significant Loss ◽

Creep Tests ◽

Supercritical Steam Parameters ◽

Steam Parameters ◽

The Impact

AbstractThe subject of the research was a material in the form of a ϕ38×4 pipe from HCM12 steel used for steam superheater coils in power boilers with supercritical and ultra-supercritical steam parameters. This article presents results of investigations of mechanical properties and microstructure of material of the examined tube in the as-received condition and after 100,000 h service at 585°C under creep conditions. Creep tests were carried out for the material after 100,000 h service to determine the disposable residual life. The impact of changes in mechanical properties and degradation of the microstructure on the loss of creep resistance compared to the as-received condition was assessed. The investigations have revealed that the examined steel after 100,000 h service meets the requirements for this steel in the as-received condition with regard to strength properties at room and elevated temperature. The creep tests have revealed a significant loss of creep resistance, which was estimated at around 60-70% compared to the as-received condition.

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A Study of the Influence of Strain Hardening and Precipitation Hardening Sequence on Development of Mechanical Properties of AlMgSi Conductor Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.690.45 ◽

2011 ◽

Vol 690 ◽

pp. 45-48

Author(s):

Tadeusz Knych ◽

Beata Smyrak ◽

Piotr Osuch ◽

Kinga Szajding

Keyword(s):

Mechanical Properties ◽

Precipitation Hardening ◽

Power Transmission ◽

Strength Properties ◽

Point Of View ◽

Artificial Ageing ◽

Wire Rod ◽

Study Results ◽

The Impact ◽

Almgsi Alloy

The paper focuses on 6xxx series AlMgSi conductor alloys. Such alloys are used for manufacturing of conductors for power transmission. Since the most current standards define as many as seven types of wires with various mechanical and electrical specifications, the existing philosophy of AlMgSi wires manufacturing technology for electrical applications has to be revised. Strength specifications of precipitation hardened AlMgSi alloys may be enhanced by strain and by precipitation hardening. Therefore from the scientific point of view identification seems to be relevant of the impact of the sequence of these mechanisms on development of final wire properties. In particular, this paper tries to answer the following question: Does the sequence of hardening mechanisms affect the development of mechanical properties of AlMgSi alloy wires? The paper presents results of a study of the impact of artificial ageing parameters of 6201 grade AlMgSi alloy wires on their final properties. The study results are presented and discussed in two parts. The first part addresses the impact of artificial aging temperature and duration on the strength properties of AlMgSi (grade 6201) alloy wire rod. The second part is focused on hardening development in the process of drawing of a AlMgSi wire made of the same alloy grade, subjected to different thermal treatments, the parameters of which have been selected based on analysis of the results of the first, wire-rod related, part of the study.

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Assessment of the Impact of Inaccuracy and Variability of Material and Selected Technological Factors on Physical and Mechanical Properties of Fresh Masonry Mortars and Plasters

Materials ◽

10.3390/ma13061382 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1382

Author(s):

Małgorzata Gołaszewska ◽

Jacek Gołaszewski ◽

Grzegorz Cygan ◽

Jerzy Bochen

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Hydrated Lime ◽

Strength Properties ◽

Technological Factors ◽

Air Content ◽

Lime Mortars ◽

Mixing Intensity ◽

The Impact ◽

Plasticizing Admixture

The article presented the analysis of the impact that various kinds of technological inaccuracies have on the properties of fresh masonry mortars and plasters. Analyzed were the inaccuracies in dosing of mortar components, namely, water, lime, and air-entraining plasticizing admixture (APA) (±10% of mass), and the effect of variable technological conditions, namely, different mixing intensity (fast, slow, normal) and temperature (5 °C, 20 °C, and 35 °C) during first 72 h after mixing. The impact of differences in the properties of cement and aerial (hydrated) lime originating from different manufacturers was also analyzed. The impact of these factors was determined for consistency, density, air content, compressive, and flexural strength. The sensitivity to changes in the analyzed properties was determined by the coefficient of variation. Changes in the dosing of constituents, mixing speed, and temperature adversely affected strength properties. For mortars with APA, these changes exceeded 20% and reached 40%. The greatest impact was evident in the consistency, especially with an excess of APA, where changes ranged from 6% to 80%. The results showed greater resistance of cement-lime mortars to changing selected technological conditions and errors in measuring the amount of ingredients than mortars with air-entraining plasticizing admixture (APA).

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Inoculation of Austenite Primary Grains in Cast Iron

Archives of Foundry Engineering ◽

10.2478/afe-2014-0084 ◽

2014 ◽

Vol 14 (4) ◽

pp. 45-48 ◽

Cited By ~ 2

Author(s):

D. Kopyciński ◽

E. Guzik ◽

A. Szczęsny ◽

J. Dorula ◽

D. Siekaniec ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Cast Iron ◽

Iron Powder ◽

Strength Properties ◽

Flake Graphite ◽

Primary Austenite ◽

Commercial Inoculant ◽

Austenite Grains ◽

The Impact

Abstract The modification is a widespread method of improving the strength properties of cast iron. The impact in terms of increasing amounts of eutectic grains has been thoroughly studied while the issue of the impact on the mechanical properties of primary austenite grains has not been studied in depth yet. The paper presents the study of both aspects. The methodology was to conduct the melting cast iron with flake graphite, then modifying the alloy by two sets of modifiers: the commercial modifier, and a mixture of iron powder with a commercial inoculant. The DAAS test was carried out to identify the primary austenite grains. The degree of supercooling was determined and the UTS test was performed as well. Additionally carried out the metallographic specimen allowing for counting grains. It can be concluded that the introduction of the iron powder significantly improved the number of austenite primary grains which resulted in an increase in tensile strength UTS.

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Mechanical properties of ductile cast iron relation to the charge elements

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1199/1/012022 ◽

2021 ◽

Vol 1199 (1) ◽

pp. 012022

Author(s):

H Pacha-Gołębiowska ◽

W Piekarska

Keyword(s):

Mechanical Properties ◽

Cast Iron ◽

Spectroscopic Studies ◽

Ductile Cast Iron ◽

Cooling Curve ◽

Cast Irons ◽

Alloying Additives ◽

Chunky Graphite ◽

Alloy Cast Iron ◽

Alloy Cast

Summary In many recent publications on the optimisation of alloys in terms of, among other things, their strength and resistance to wear, a trend can be observed to look for new alloying additives to improve these properties. This paper presents the results of a study on the effect of changes in the chemical composition of EN-GJS-500-7 ductile alloy cast iron on its mechanical properties. In order to confirm the effect of alloying additives on the mechanical properties of the alloys, industrial melting of cast iron was carried out and samples were taken for testing. The smelts were not subjected to heat treatment, but were carried out differently in terms of the feedstock used and based on the analysis of the cooling curve using an automated smelting technology enabling the elimination of degraded Chunky graphite. The influence of the shape of graphite precipitates on tensile strength and hardness was determined, and spectroscopic studies of the microstructure of cast irons were carried out.

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Heat Treatment of 10Cr12Ni3Mo2VN Blade Steel for Ultra Supercritical Unit

Materials Science Forum ◽

10.4028/www.scientific.net/msf.817.472 ◽

2015 ◽

Vol 817 ◽

pp. 472-478

Author(s):

Jun Ru Li ◽

Chen Gong ◽

Le Yu Zhou ◽

Lie Chen ◽

Hui Zuo ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Impact Toughness ◽

Strength Properties ◽

Quenching Temperature ◽

Tempering Temperature ◽

The Impact ◽

Quenching And Tempering ◽

Blade Steel ◽

Tempering Process

In this work, the effects of final heat treatment including quenching and tempering process on mechanical properties of 10Cr12Ni3Mo2VN steel were investigated by orthogonal experimental. It is shown that, the quenching process had a small effect on the strength properties. But the impact property obviously decreased with the increase of quenching temperature, that is due to the grain coarsening. It can be found that tempering temperature is the major factor which affects the mechanical properties. Tempering process had a large effect on the precipitation of carbides and that affected the strength, toughness and plastic greatly. The impact toughness had a minimum after tempered at 650°C between 600°C~700°C. The experimental results show that the M23C6 type carbides precipitated at the grain and martensite lath boundary were the main reason which decreased the impact toughness when tempering temperature increased from 600°C to 650°C.

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Sheet metal with variable mechanical properties over its thickness

Izvestiya Ferrous Metallurgy ◽

10.17073/0368-0797-2019-8-587-593 ◽

2019 ◽

Vol 62 (8) ◽

pp. 587-593

Author(s):

A. B. Maksimov ◽

I. P. Shevchenko ◽

I. S. Erohina

Keyword(s):

Mechanical Properties ◽

Yield Strength ◽

Rupture Strength ◽

Strength Properties ◽

Deformation Resistance ◽

Strength Characteristics ◽

Load Application ◽

Bending Test ◽

Accelerated Cooling ◽

The Impact

The influence of one-sided accelerated cooling of A32 plate shipbuilding steel with thickness of 10·10–3 m on structure and mechanical properties was investigated. As a result of such cooling, continuous spectrum of microstructures from ferrite-bainite on the rapidly cooled surface to ferrite-perlite on the opposite surface is formed along the billet thickness. Therefore, over the billet thickness strength properties are reduced from rapidly cooled surface to the opposite one. Thus, the gradient of strength characteristics (hardness, yield strength and rupture strength) along the billet thickness is directed to rapidly cooled surface. For comparative analysis, other batches of billets were subjected to normalization and hardening with high tempering. The analysis of mechanical properties has shown that strength and plastic properties of the samples at unilateral accelerated cooling are at level of heat-strengthened state. Testing on impact strength of the samples with variable distribution of mechanical properties over their thickness has shown that the impact depends on correlation of gradient directions of strength properties and load application. In impact bending test at the temperature of –40 °C, if the direction of load application is opposite to gradient of strength properties, the impact work was more than 300 J (the sample did not collapse). At coincidence of directions of the gradient deformation resistance and load, energy of the blow was 262 J. Thus, if the direction of deformation resistance gradient coincides with the direction of external applied load, then it leads to an increase in plasticity of steel. It is shown that, knowing distribution of strength characteristics over the sample thickness, it is possible to calculate integral values of yield strength and rupture strength of the sample. Value of relative through-thickness elongation increases from the rapidly cooled surface to the opposite one. Integral elongation of the billet is less than the smallest relative through-thickness elongation. With changing thickness strength of the billet during bending, displacement of the neutral deformation line relative to the geometrically average line in the direction of the strength properties gradient is inevitable. The position of neutral line of deformation during bending is proposed to be determined by the value of experimental integral yield strength (rupture strength).

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