scholarly journals Optimization of the combined explosion hardening processes

2021 ◽  
Vol 280 ◽  
pp. 07018
Author(s):  
Viktor Shchetynin ◽  
Roman Arhat ◽  
Vladimir Drahobetskyi ◽  
Vyacheslav Puzyr ◽  
Dmitriy Maloshtan
Keyword(s):  
Wear Resistance ◽  
Lagrange Function ◽  
Extremum Problem ◽  
Mining Equipment ◽  
Explosive Cladding ◽  
New Methods ◽  
Conditional Extremum ◽  
Nonlinear Programming Methods ◽  
First Time ◽  
Strength And Ductility

The proposed method for calculating the loading parameters makes it possible to determine the wear parameters after explosion hardening. The calculation method is simple and less time consuming compared with calculation methods that involve the use of nonlinear programming methods. The main methods of increasing the wear resistance of mining equipment parts using explosion methods are generalized. The reserve for increasing the wear resistance consists in the optimization of deformation parameters during the power and thermal intensification of processes and the development of new methods and technologies of hardening. The factors (parameters) of the studied processes: explosive cladding, alloying, hardening, are formulated. Optimization of the processes under consideration is possible by decomposing the process into simpler ones with subsequent optimization of the parameters of these processes and the synthesis of the obtained solutions. For the first time, a solution to the multicriteria problem of two-stage explosion hardening is presented. It is proposed to split the process into simpler ones. Optimization criteria are proposed for each of the simplified processes. The problem is reduced to a conditional extremum problem, which is solved by composing the Lagrange function. By transforming the wear equation, the optimal ratio of strength and ductility for parts operating under abrasive wear conditions is determined.

On effect of surface hardening on impact and abrasive wear resistance of Hadfi eld steel

2020 ◽  
pp. 252-255
Author(s):  
V.I. Bolobov ◽  
V.S. Bochkov ◽  
E.V. Akhmerov ◽  
V.A. Plashchinsky ◽  
E.A. Krivokrisenko E.A.
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Work Hardening ◽  
Surface Hardening ◽  
Cold Work ◽  
Abrasive Wear Resistance ◽  
Hadfield Steel ◽  
Mining Equipment ◽  
Effect Of Surface

On the example of Hadfield steel, as the most common material of fast-wearing parts of mining equipment, the effect of surface hardening by plastic deformation on their impact and abrasive wear resistance is considered. Wear test is conducted on magnetic ironstone as typical representative of abrasive and hard rock. As result of wear of initial samples with hardness of ∼200 HB and samples pre-hardened with different intensities to the hardness of 300, 337 and 368 HB, it is found that during the initial testing period, the initial samples pass the “self-cold-work hardening” stage with increase in hardness to ∼250 HB, which remains virtually unchanged during further tests; the hardness of the pre-hardened samples does not change significantly throughout the tests. It is established that the rate of impact-abrasive wear of pre-hardened samples is significantly (up to 1.4 times) lower than the original ones that are not subjected to plastic deformation, and decreases with increasing degree of cold-work hardening. Preliminary surface hardening by plastic deformation can serve as effective way to increase the service life of fast-wearing working parts of mining equipment.

scholarly journals Efficient TALEN-mediated gene knockin at the bovine Y chromosome and generation of a sex-reversal bovine

2021 ◽  
Author(s):  
Ming Wang ◽  
ZhaoLin Sun ◽  
Fangrong Ding ◽  
Haiping Wang ◽  
Ling Li ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Nuclear Transfer ◽  
Sex Reversal ◽  
Practical Application ◽  
Transcription Activator ◽  
New Methods ◽  
Fetal Fibroblasts ◽  
Male Phenotype ◽  
Solid Foundation ◽  
First Time

AbstractFunctional elucidation of bovine Y-chromosome genes requires available genome editing technologies. Meanwhile, it has yet to be proven whether the bovine Sry gene is the main or single factor involved in the development of the male phenotype in bovine. Here, we efficiently knocked out four Y-linked genes (Sry, ZFY, DDX3Y, and EIF2S3Y) in bovine fetal fibroblasts (BFFs) with transcription activator-like effector nucleases (TALENs) individually. Furthermore, we used TALEN-mediated gene knockin at the Sry gene and generated a sex-reversal bovine by somatic cell nuclear transfer (SCNT). The resulting bovine had only one ovary and was sterile. We demonstrate, for the first time, that the Sry gene is an important sex-determining gene in bovine. Our method lays a solid foundation for detecting the biology of the bovine Y chromosome, as it may provide an alternative biological model system for the study of mammalian sex determination, and new methods for the practical application in agricultural, especially for sex predetermination.

ONLINE EXHIBITION METROLEXPO-2020. ACCURATE MEASUREMENTS ARE THE BASIS OF QUALITY AND SAFETY

2021 ◽  
pp. 50-57
Author(s):  
V. I. Matveev
Keyword(s):  
Measuring Equipment ◽  
Technical Diagnostics ◽  
Quality And Safety ◽  
New Methods ◽  
Analytical Studies ◽  
Functional Control ◽  
First Time

The article summarizes the results of the MetrolExpo exhibition, which was held for the first time online. The event focused on instrumentation-demonstration and discussion of the possibilities of modern measuring equipment, analysis of new methods and technologies of accurate measurements that have appeared in recent years. The latest developments, devices and systems for conducting measurements, tests, technical diagnostics, analytical studies, production and functional control from the largest Russian and foreign manufacturers were demonstrated.

Effect of the Morphology, Size, Distribution and Homogeneity of Carbides and Matrix on Wear Resistance in High Cr-Alloys White Cast Iron

2021 ◽  
Vol 1016 ◽  
pp. 56-62
Author(s):  
Carlos Camurri ◽  
Jasmín Maril ◽  
Eric Romero
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
White Cast Iron ◽  
Wear Behavior ◽  
Hardness Test ◽  
Mining Equipment ◽  
Cast Irons ◽  
Loss Of Mass ◽  
Ultimate Purpose ◽  
Wear Tests

The aim of this work was to study the wear behavior of high-chromium white cast iron of families ASTM A-532 II (B, D) and III A, used in mining equipment, in order to establish relationships between the wear resistance, hardness and microstructure of the alloys, with the ultimate purpose of predicting their resistance to abrasion. Samples from these cast irons were subjected to mechanical wear tests by rotating drum, then their micro/macro hardness was measured and microstructure analyzed by optical and scanning electron microscopy .It was found that when the macroscopic hardness differences were significant there was a strong correlation between the hardness and the loss of mass due to abrasion-impact wear. By contrast, when the alloys had similar hardness, the wear resistance was determined by morphology, size, and the distribution and connectivity of carbides and matrix and therefore was not predictable by an only simple hardness test.

Toward the Development of AHSS for Wear Resistant Applications

2018 ◽  
Vol 941 ◽  
pp. 568-573 ◽  
Author(s):  
Preston Wolfram ◽  
Christina Hensley ◽  
Ronald Youngblood ◽  
Rachael Stewart ◽  
Emmanuel de Moor ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Retained Austenite ◽  
Process Development ◽  
High Strength ◽  
Advanced High Strength Steel ◽  
Wear Resistant ◽  
Transformation Induced Plasticity ◽  
Enhance Wear Resistance ◽  
Improve Wear Resistance ◽  
Strength And Ductility

Advanced High Strength Steel (AHSS) developments have largely focused on automotive applications using metallurgical approaches to develop retained austenite-containing microstructures in a variety of new steels, using the transformation-induced plasticity (TRIP) effect to achieve better combinations of strength and ductility. These efforts have been extended in recent studies to explore the potential to improve wear resistance, using metastable retained austenite to enhance wear resistance for earth-moving and other applications. This paper provides selected highlights of the authors’ efforts to develop wear resistant steels using AHSS processing approaches. Some attractive product/process development opportunities are identified, and it appears that martensite-austenite microstructures produced using “quenching and partitioning” exhibit increased wear resistance.

High-Current Pulsed Electron Treatment of Hypoeutectic Al–10Si Alloy

2017 ◽  
Vol 36 (1) ◽  
pp. 97-100 ◽  
Author(s):  
Lu Diankun ◽  
Gao Bo ◽  
Zhu Guanglin ◽  
Lv Jike ◽  
Hu Liang
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Beam Energy ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Surface Nanocrystallization ◽  
Primary Si ◽  
Beam Energy Density ◽  
Eutectic Si ◽  
First Time

AbstractThis paper reports, for the first time, an analysis of the effect of high-current pulsed electron beam (HCPEB) on a hypoeutectic Al–10Si alloy. The Al–10Si alloy was treated by HCPEB in order to see the potential of this fairly recent technique in modifying its wear resistance. For the beam energy density of 3 J/cm2 used in the present work, the melting mode was operative and led to the formation of a “wavy” surface and the absence of mass primary Si phase and eutectic microstructure. The surface nanocrystallization of primary and eutectic Si phases led to the increase in macro-hardness of the top surface layer, and the wear resistance was drastically improved with a factor of 4.

The Monitoring Data Analysis of Cover System in Subway Station

2011 ◽  
Vol 94-96 ◽  
pp. 1814-1817
Author(s):  
Ming Li Huang ◽  
Shu Feng Pei ◽  
Wen Zheng Wang ◽  
Hua Kuan Liu
Keyword(s):  
Wear Resistance ◽  
Data Analysis ◽  
System Design ◽  
Monitoring Data ◽  
Subway Station ◽  
Cover System ◽  
First Time

Fengtail North Road Station uses a open and cover combination of laying fabricated strap method for the first time, so we monitor the Cover system very closely. We draw schedule curves and analysis the monitoring data for the main component’s monitoring projects of the Cover system. Results show that the deformation values of the components of the Cover system are small, but the values of piles top displacement and settlement are large, at the same time, the lattices of Cover boards have good wear-resistance ability. The conclusion has very great help for optimizing the system design and the promotion of laying fabricated strap method.

Producing Steels with Special Properties Using a Jet Heat Treatment System

2020 ◽  
Vol 854 ◽  
pp. 30-36
Author(s):  
Yuri V. Gulkov ◽  
Anna V. Turysheva ◽  
Irina V. Vinogradova
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Steel Production ◽  
High Wear Resistance ◽  
Mining Equipment ◽  
Steel Company ◽  
Iron And Steel ◽  
Technological Complex ◽  
Metal Market

The prospects of production of special properties steels in the Russian and global metal market are estimated. The necessity of using new types of steels is substantiated. The prospects of introducing steels with special properties developed by PJSC “Magnitogorsk Iron and Steel Company” to the market are determined. Evaluation of measures for the production of large volumes of products showed that there is a problem of a significant increase in the time of manufacturing and delivery of output products to the consumer. As measures to ensure the modernization of the technological complex of the steel enterprise and reduce the time for steel production, the system of jet heat treatment of metal is proposed. According to the results of comparative analysis of the MAGSTRONG H500 and HARDOX 500 alloys used in mining equipment under conditions of increased wear, it was revealed that the proposed method of heat treatment allows one to achieve high wear resistance properties, with high coefficients of tensile strength and toughness.

Improving Matsui’s Search Algorithm For The Best Differential/Linear Trails And Its Applications For DES, DESL And GIFT

2020 ◽  
Author(s):  
Fulei Ji ◽  
Wentao Zhang ◽  
Tianyou Ding
Keyword(s):  
Search Algorithm ◽  
Search Space ◽  
Search Methods ◽  
New Methods ◽  
Linear Layer ◽  
Speed Up ◽  
Automatic Search ◽  
The Cost ◽  
First Time ◽  
Improved Algorithm

Abstract Automatic search methods have been widely used for cryptanalysis of block ciphers, especially for the most classic cryptanalysis methods—differential and linear cryptanalysis. However, the automatic search methods, no matter based on MILP, SMT/SAT or CP techniques, can be inefficient when the search space is too large. In this paper, we propose three new methods to improve Matsui’s branch-and-bound search algorithm, which is known as the first generic algorithm for finding the best differential and linear trails. The three methods, named reconstructing DDT and LAT according to weight, executing linear layer operations in minimal cost and merging two 4-bit S-boxes into one 8-bit S-box, respectively, can efficiently speed up the search process by reducing the search space as much as possible and reducing the cost of executing linear layer operations. We apply our improved algorithm to DESL and GIFT, which are still the hard instances for the automatic search methods. As a result, we find the best differential trails for DESL (up to 14-round) and GIFT-128 (up to 19-round). The best linear trails for DESL (up to 16-round), GIFT-128 (up to 10-round) and GIFT-64 (up to 15-round) are also found. To the best of our knowledge, these security bounds for DESL and GIFT under single-key scenario are given for the first time. Meanwhile, it is the longest exploitable (differential or linear) trails for DESL and GIFT. Furthermore, benefiting from the efficiency of the improved algorithm, we do experiments to demonstrate that the clustering effect of differential trails for 13-round DES and DESL are both weak.

The Preparation and Low-Frequency Vibrational Spectra of Some Copper(I) and Silver(I) Alkane- and Arene-monothiolate Complexes

1979 ◽  
Vol 32 (7) ◽  
pp. 1443 ◽  
Author(s):  
GA Bowmaker ◽  
L Tan
Keyword(s):  
Raman Spectra ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
New Methods ◽  
Thiolate Complexes ◽  
New Compounds ◽  
First Time ◽  
Far Infrared Spectra

A number of different methods for preparing anionic Group 1B metal thiolate complexes have been investigated. The compounds [Me4N] [CU2(SMe)3] and [Et4N] [Ag5(SBut)6] are reported for the first time, and new methods for preparing the previously known compounds [Et4N] [Cu5(SBut)6], [Me4N]2 [CU5(SPh)7] and [Et4N]2 [Cu5(SPh)7] are described. The far-infrared spectra of the above compounds, and of CuSMe, CuSBut, AgSBut, [Me4N]2 [CU4(SPh)6] and [Me4N]2 [Ag5(SPh)7] have been obtained, and metal-sulfur stretching bands are assigned in the 150-350 cm-1 region. The low-frequency Raman spectra have also been obtained for some of these compounds. Possible structures for the new compounds are considered in the light of the low-frequency vibrational spectra.

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