scholarly journals Influence of boron modification and cooling conditions during solidification on structural and phase state of heat- and wear-resistant white cast iron

2019 ◽  
Vol 62 (11) ◽  
pp. 887-893
Author(s):  
V. M. Kolokol’tsev ◽  
E. V. Petrochenko ◽  
O. S. Molochkova
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Form Factor ◽  
Cast Iron ◽  
Chemical Composition ◽  
White Cast Iron ◽  
Dendrite Structure ◽  
Wear Resistant ◽  
Boron Modification ◽  
Secondary Carbides

The paper is devoted to examination of the effect of boron modification and temperature conditions for metal cooling in a mold on phase composition, morphology and chemical composition of structural components of heatand wear-resistant white cast iron of Fe – C– Cr– Mn – Ni – Ti–Al – Nb system. The phase composition of the metallic base changed from the dualphase (α- and γ-phases) to the completely single-phase (γ-phase). Boron modification influenced on the type of secondary carbides, while secondary hardening in a mold occurs through extraction of dispersed niobium carbides (without boron, but with chromium carbides). The structure of modified cast iron is presented by the primary complex carbides (Ti, Nb, Cr, Fe)C, as well as by solid solution dendrites, eutectics and secondary carbides MeC. Boron addition changes the chemical composition of primary carbides with decrease of niobium content from 44 to 2 % and increase of titanium content from 24 to 65 %; content of eutectic carbides rises as well. As for hypereutectic carbides, they are characterized by increase of ferrum content and lowering of chrome content. Parameters of the primary phases (MeC carbides and solid solution dendrites) were investigated using the methods of quantitative metallography. The special technique of Thixomet PRO image analyzer was used for evaluation of the F form factor which is the criterion of compatibility of the primary phases. The following parameters were used in this work as the parameters of dendrite structure: dispersity of the dendrite structure (δ), volumetric part of dendrites (V), distance between the axes of second order dendrites (λ2 ), form factor (F), average dimensions of dendrites – square (S), length (l) and width (β). All the suggested characteristics (parameters) allowed not only to provide quantitative evaluation of the dendrite structure, but also to determine modification degree as relative variation (in %) of each criterion in modified cast iron in comparison with non-modified iron. Quantitative relation between modification degree and crystallization conditions were established as well.

scholarly journals Optimization of chemical composition in the manufacturing process of flotation balls based on intelligent soft sensing

2016 ◽  
Vol 70 (6) ◽  
pp. 603-612 ◽  
Author(s):  
Nedeljko Ducic ◽  
Zarko Cojbasic ◽  
Radomir Slavkovic ◽  
Branka Jordovic ◽  
Jelena Purenovic
Keyword(s):  
Neural Network ◽  
Cast Iron ◽  
Chemical Composition ◽  
White Cast Iron ◽  
Soft Sensor ◽  
Sensor Data ◽  
Production Processes ◽  
Artificial Neural Network Ann ◽  
Genetic Combination ◽  
Minimum Wear

This paper presents an application of computational intelligence in modeling and optimization of parameters of two related production processes - ore flotation and production of balls for ore flotation. It is proposed that desired chemical composition of flotation balls (Mn=0.69%; Cr=2.247%; C=3.79%; Si=0.5%), which ensures minimum wear rate (0.47 g/kg) during copper milling is determined by combining artificial neural network (ANN) and genetic algorithm (GA). Based on the results provided by neuro-genetic combination, a second neural network was derived as an ?intelligent soft sensor? in the process of white cast iron production. The proposed ANN 12-16-12-4 model demonstrated favourable prediction capacity, and can be recommended as a ?intelligent soft sensor? in the alloying process intended for obtaining favourable chemical composition of white cast iron for production of flotation balls. In the development of intelligent soft sensor data from the two real production processes was used.

scholarly journals Microstructural evolution during austempering of a ASTM A-532 CLASS III type high chromium white cast iron undergoing abrasive wear

2017 ◽  
Vol 26 (46) ◽  
Author(s):  
Oscar Fabián Higuera-Cobos ◽  
Jeison Bucurú-Vasco ◽  
Andrés Felipe Loaiza-Patiño ◽  
Mónica Johanna Monsalve-Arias ◽  
Dairo Hernán Mesa-Grajales
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Cast Iron ◽  
Chemical Composition ◽  
Abrasive Wear ◽  
Retained Austenite ◽  
White Cast Iron ◽  
Abrasive Wear Resistance ◽  
Class Iii ◽  
High Chromium

This paper studies the influence of variables such as holding temperatures and times during austempering of High Chromium White Cast Iron (HCWCI), with the following chemical composition: Cr 25 %, C 3 %, Si 0.47 %, Mn 0.74 % and Mo 1.02 %. The aim of the austempering was to modify the percentage of retained austenite and its correlation to abrasive wear resistance under different conditions.Microhardness tests, SEM-EDS and XRD were performed to determine mechanical properties, chemical composition, and type of carbides and microstructures present, respectively. The tests complied with the ASTM G-65 standard. Results showed that the best performance against abrasion was achieved for austempering at 450 ºC with holding time of 6 hours.

Formation of structural parameters and mechanical properties of multi-element coatings based on niobium nitride under different deposition conditions

2021 ◽  
pp. 67-72
Author(s):  
V.P. Tabakov ◽  
A.V. Chikhranov ◽  
Ya.A. Dolzhenko
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Chemical Composition ◽  
Deposition Temperature ◽  
Chemical Elements ◽  
Structural Parameters ◽  
Niobium Nitride ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Deposition Conditions

The results of the dependence of the chemical composition of coatings based on niobium nitride on the layout of the installation are presented. The effect of the chemical elements content in coatings based on niobium nitride on the phase composition, structural parameters and mechanical properties is determined. The effect of the deposition temperature of coatings on the mechanical properties of wear-resistant coatings is studied.

scholarly journals Structure and Mechanical Properties of Explosive Welded Mg/Al Bimetal/ Struktura I Właściwości Mechaniczne Połączenia Uzyskanego Metodą Zgrzewania Wybuchowego Bimetalu Mg/Al

2014 ◽  
Vol 59 (4) ◽  
pp. 1593-1597 ◽  
Author(s):  
D. Balga ◽  
D. Ostroushko ◽  
K. Saksl ◽  
E. Mazancová ◽  
O. Milković
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Phase Composition ◽  
Chemical Composition ◽  
Phase Transformations ◽  
Explosion Welding ◽  
Lattice Parameters ◽  
Diffraction Experiment ◽  
X Ray ◽  
Cubic Phases

Abstract In the article we analyzed shape, local mechanical properties, chemical and phase composition of Magnesium/Aluminium cladded material prepared by explosion welding. In particular we focus our investigation on Mg/Al interface and areas close to the joint. Hardness of the joined materials measured far from their interface is similar for both materials, however in the region of interface the hardness drops down by 40%. Phase transformations in the interface was examined by a hard X-ray micro-diffraction experiment performed at beamline P07 at PETRA III at the energy of 99 keV which helped us identify in Al: fcc-Al, Al2Cu tetragonal and Al7Cu2Fe tetragonal and in Mg: hcp-Mg, Mg2Si cubic phases. In the interface we haven’t observed any new intermetallics, but computation of lattice parameters and profiles of Al and Mg peaks proved an existence of solid solution with different gradient of chemical composition.

scholarly journals Effect of Microstructure of Fe-C-V Alloys on Selected Functional Properties

2014 ◽  
Vol 14 (3) ◽  
pp. 33-36 ◽  
Author(s):  
M. Kawalec ◽  
J. Kozana
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Chemical Composition ◽  
White Cast Iron ◽  
High Wear Resistance ◽  
Cast Alloys ◽  
Vanadium Carbides ◽  
Good Workability ◽  
Conventional Machining ◽  
Very High

Abstract The cast alloys crystallizing in Fe-C-V system are classified as white cast iron, because all the carbon is bound in vanadium carbides. High vanadium cast iron has a very high abrasion resistance due to hard VC vanadium carbides. However, as opposed to ordinary white cast iron, this material can be treated using conventional machining tools. This article contains the results of the group of Fe-C-V alloys of various microstructure which are been tested metallographic, mechanical using an INSTRON machine and machinability with the method of drilling. The study shows that controlling the proper chemical composition can influence on the type and shape of the crystallized matrix and vanadium carbides. This makes it possible to obtain a high-vanadium cast iron with very high wear resistance while maintaining a good workability.

scholarly journals Karakterisasi Grinding Balls Produksi CV Baja Ellips

2018 ◽  
Vol 3 (1) ◽  
pp. 19-25
Author(s):  
Arianto Leman ◽  
Tiwan Tiwan ◽  
Nurdjito Nurdjito
Keyword(s):  
Cast Iron ◽  
Chemical Composition ◽  
White Cast Iron ◽  
The Other ◽  
Grinding Balls ◽  
Medium Strength

This research is aimed to study the characteristics of cast grinding balls produced by CV Baja Ellips Ceper, Klaten. The samples were taken from three tapping. One group was quenched in water while the other was not. The studied characteristics comprised of chemical composition, microstructure, hardness and wear. The result shows that the grinding balls have the chemical composition of medium-strength cast iron. However, the microstructure shows cementite and pearlite that indicates the structure of a white cast iron. The hardness of quenched and unquenched grinding balls are 60 HRC and 57 HRC, respectively. The hardness is consistent from the edges to the middle of the grinding balls. The specific wear of quenched grinding balls and unquenched grinding balls is 3.32963 x 10-06 mm2/kg and 5.032 x 10-06 mm2/kg, respectivelyPenelitian ini bertujuan untuk mengetahui karakteristik grinding balls produksi CV Baja Ellips Ceper Klaten yang dibuat dengan menggunakan proses pengecoran. Sampel grinding balls diambil dari tiga kali tapping yang berbeda. Satu kelompok dicelup dingin dalam air dan yang tidak dicelup dingin. Karakterisasi yang dilakukan meliputi komposisi kimia, struktur mikro, kekerasan dan keausan. Hasil penelitian menunjukkan bahwa komposisi kimia dari bola penggiling termasuk dalam kelas besi tuang kekuatan sedang. Struktur mikro yang tampak adalah sementit dan perlit yang menunjukkan struktur besi tuang putih. Kekerasan grinding balls yang dicelup dingin adalah 60 HRC sedangkan yang tanpa dicelup dingin sebesar 57 HRC. Kekerasan grinding balls konsisten dari bagian tepi sampai bagian tengah. Keausan spesifik grinding balls yang dicelup dingin dan tanpa dicelup dingin berturut-turut 3,32963 x 10-06 mm2/kg dan 5,032 x 10-06 mm2/kg

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