scholarly journals Automation of Batch Casting of Cast Iron Melts in the Chill Mold in the Production of Castings of Machine Parts for the Mining Industry

2020 ◽  
pp. 163-169
Author(s):  
Viktor Lomakin ◽  
◽  
Viktor Pukalov ◽  
Viktor Dubodelov ◽  
Maksim Goryuk ◽  
...  
Keyword(s):  
Cast Iron ◽  
Operating Time ◽  
Mining Industry ◽  
Metal Casting ◽  
Electromagnetic System ◽  
High Productivity ◽  
Control Scheme ◽  
Basic Parameters ◽  
Chill Mold ◽  
Dosage Error

The analysis of the basic parameters of the dosage of molten iron in metal forms using the magnetodynamic installation MDN-6CH. A schematic diagram has been developed for controlling the electromagnetic systems of the unit. The technology of dosing and pouring metal into the chill mold has been developed in the manufacture of cast iron balls with a diameter of 40 and 120 mm. At the optimal casting temperature, the electrical parameters of the inductor (voltage Ui, current Ii, power Ri) were in the range Ui = 250-300 V, Ii = 480-520 A, Ri = 140-160 kW. When reducing the mass of metal in the crucible MDN-6CH using a control scheme made switching inductor from a voltage of 300 V to 250 V. The power was reduced by 15-20 kW, and the temperature of the metal remained within the tolerance of the technology of metal casting. Using the adopted dosing scheme, it became possible to cast metal at constant parameters of the electromagnetic system and the time of pouring. The technology of dispensing and pouring metal into the mold for the production of cast iron balls with a diameter of 40 and 120 mm was carried out at an inductor voltage of 300 V, and the electromagnet - 220 V. The initial level of metal on the drain socket was equal to 20 mm. The molding time of molds in the manufacture of balls with a diameter of 40 mm was 7.3 s, and balls with a diameter of 120 mm - 16.2 s. The operating time of the electromechanical actuator was set in the manufacture of balls with a diameter of 40 mm - 0.35 s, and balls with a diameter of 120 mm - 0.75s. The consumption of metal in the manufacture of balls with a diameter of 40 and 120 mm was in the range of 0.7-0.75 kg / s and 1.65-1.70 kg / s, respectively. The metal casting was carried out at temperatures of 1320-1340 ° C and 1360-1380 ° C. The dosage accuracy was determined by weighing the metal of the poured balls and the molding system of the mold. Mathematical processing of the results of the dosing showed that in the manufacture of balls with a diameter of 40 mm at a temperature of 1320 °C the error of dosing is 10-11%. With increasing iron temperature, the dosage error decreases and at a metal temperature of 1370 °C is 5-6%. In the manufacture of balls with a diameter of 120 mm at a temperature of iron 1330, the dosage error is 7-8%, and at a temperature of 1360 ° C - 3-4%. The study of the characteristics of the casting and dosing process of cast iron in the chill mold allowed us to develop the technology of casting cast iron melts, which provided the required metering accuracy and high productivity of the conveyor production of grinding bodies.

scholarly journals Molybdenum alloying in cast iron and steel

2019 ◽  
Vol 8 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Xiang-Ru Chen ◽  
Qi-Jie Zhai ◽  
Han Dong ◽  
Bao-Hua Dai ◽  
Hardy Mohrbacher
Keyword(s):  
Cast Iron ◽  
Production Cost ◽  
Complex Shape ◽  
Mining Industry ◽  
Metal Casting ◽  
Alloying Element ◽  
Large Share ◽  
Steel Alloys ◽  
Iron And Steel ◽  
Iron Based

AbstractMetal casting is an important manufacturing technology for efficiently producing massive components with complex shape. A large share of industrial castings is made from iron and steel alloys, combining attractive properties and low production cost. Upgrading of properties in cast iron and steel is mainly achieved by alloying and in fewer cases by heat treatment. Molybdenum is an important alloying element in that respect, increasing strength, hardness and toughness. It also facilitates particular heat treatments such as austempering. The paper describes the metallurgical functionality of molybdenum alloying in iron-based castings and demonstrates its effectiveness for applications in the automotive and mining industry.

A Study on Modified Model Predictive DPC of Rectifiers

2013 ◽  
Vol 441 ◽  
pp. 328-331
Author(s):  
Hui Zhao ◽  
Biao Wang ◽  
Hong Jun Wang ◽  
You Jun Yue
Keyword(s):  
Power Control ◽  
Reactive Power ◽  
Operating Time ◽  
Sampling Period ◽  
Switching Frequency ◽  
Direct Power ◽  
Direct Power Control ◽  
Voltage Vector ◽  
Control Scheme ◽  
Result Show

In this paper, we study a modified predictive direct power control scheme (P-DPC).This scheme which based on model predictive control (MPC) uses a discrete rectifier model to infer the predictive direct power control theme again, and selects the operating time of voltage vector and voltage vector to realize fixed switching frequency through setting the minimum power errors of each sampling period. This control scheme has a lower switching frequency compared to MP-DPC; and it is still simple and clear implemented in the stationary reference frame directly, meanwhile, it does not need PI controllers or voltage-oriented controllers compared to other developed control schemes. We make simulations using MATLAB. The result show the excellence of this novel predictive direct power control scheme through improving the switching frequency, current THD and active power and reactive power quality compared to MP-DPC and LUT-DPC.

The influence of titanium addition on wettability of high-chromium white cast iron-matrix composites

2018 ◽  
Vol 53 (11) ◽  
pp. 1567-1576 ◽  
Author(s):  
Takalani Madzivhandila ◽  
Shepherd Bhero ◽  
Farouk Varachia
Keyword(s):  
Cast Iron ◽  
White Cast Iron ◽  
Mining Industry ◽  
Titanium Content ◽  
High Wear Resistance ◽  
Matrix Composites ◽  
Ferrous Alloys ◽  
Titanium Addition ◽  
High Chromium ◽  
Wetting Properties

The mining industry exerts ever increasing demand for components with high wear resistance to the extent that plain ferrous alloys are falling short. Innovative metal-matrix composites non-ferrous metals have been widely researched and used. Casting composites based on ferrous alloys pose monumental challenges in casting. First, the density differential results in large buoyant forces on the ceramic such that unless a rigid structure is configured, the less dense ceramic floats on the metal stream. Second, the poor wetting properties between metal and ceramic will result in inferior bonding of the matrix, hence separation of solids in service. The paper attempts to improve the bonding characteristics of zirconia and alumina through wettability studies. High-chromium white cast iron was used as a substrate. The wetting behavior of molten iron on the substrates of zirconia and alumina was investigated. The study shows that alumina is poorly wetted with copper and nickel; the wetting angles were higher than 90°. Thus, the envisaged coating of alumina with copper or nickel prior to casting of ferrous melts will not significantly alter or improve wettability of alumina. Between copper and nickel, nickel has better bonding with alumina than copper. Titanium in high-chromium white cast iron was found to improve the wetting characteristics on alumina. The wetting angle decreased with increased titanium content.

Surface Integrity of a High Speed Milling FC300 Gray Cast Iron

2013 ◽  
Vol 465-466 ◽  
pp. 642-646 ◽  
Author(s):  
Abu Bakar Mohd Hadzley ◽  
Mohamad Raffi Nurul Fatin ◽  
Raja Abdullah Raja Izamshah ◽  
Nur Izan Syahriah Hussein ◽  
Ahmad Siti Sarah ◽  
...  
Keyword(s):  
Cast Iron ◽  
Automotive Industry ◽  
High Speed ◽  
Gray Cast Iron ◽  
Gray Cast ◽  
Surface Finishing ◽  
High Speed Machining ◽  
High Productivity ◽  
Die Surface ◽  
End Mills

The high speed machining (HSM) of gray cast iron for manufacture mold and dies involve many different cutting tool from deep hole drills to smallest ball nose end mills [. Due to the demand of fast and high productivity, high speed machining (HSM) has been increasingly used to produce mold and dies that are mostly used in automotive industry especially for stamping dies components. The process of HSM sometimes combined together with manual polishing to enhance the die surface into fine mirror finish. Although the manual polishing strongly depends by experience and skill of workers, this technique is the preferable option for polishing of moulds and dies. However, such extensive manual polishing will provide some drawback because of many human factors such as pressure and technique of polishing individual person uses. Therefore, the application high speed machining in manufacturing is still demanding as it can improve surface finishing by reducing manual polishing, reportedly account for up to 30% of the total time [2].

scholarly journals AVAILABILITY SIMULATION AND ANALYSIS OF ARMORED FACE CONVEYOR MACHINE IN LONGWALL MINING

2021 ◽  
Vol 36 (2) ◽  
pp. 69-82
Author(s):  
Raziye Norouzi Masir ◽  
Mohammad Ataei ◽  
Farhang Sereshki ◽  
Ali Nouri Qarahasanlou
Keyword(s):  
Coal Mining ◽  
Longwall Mining ◽  
Production Systems ◽  
Operating Time ◽  
Mining Industry ◽  
Production Costs ◽  
Machine Failure ◽  
Tabas Coal Mine ◽  
The Mean ◽  
Criticality Index

Since coal mining production systems are very complex, repairing equipment is expensive. If a system failure occurs, it will cause disturbances such as inoperable equipment, reduced operating time, increased production costs, and reduced equipment performance. Therefore, it is necessary to consider the availability of the coal mining industry more than ever. For this purpose, the Armored Face Conveyor (AFC) machine failure data was gathered over a period of 29 months from the Tabas Coal Mine. Descriptive statistics, trends, and serial correlation tests of the data were calculated. Then, the system’s mean and point availability were simulated. Based on the results, the mean availability (all events) and point availability (all events) at 360000 h are 96% and 95%, respectively. The mean time to first failure (MTTFF) of the AFC machine was about 23.61 h. The ReliaSoft Failure Criticality Index, ReliaSoft Downing Event Criticality Index, and ReliaSoft Downtime Criticality Index electrical equipping have the largest effect, whereas the main drive subsystem is the least important. Analysis showed that availability has a direct correlation to activity management and improvements in the quality, efficiency, and the product extraction.

scholarly journals Development of Soil Test Based Fertilizer Prescription Equations for Chrysanthemum on Alfisol

2021 ◽  
Vol 108 (june) ◽  
pp. 1-5
Author(s):  
Balamurugan J ◽  
◽  
Santhi R ◽  
Maragatham S ◽  
Gopalakrishnan M ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Field Experiments ◽  
Nutrient Management ◽  
Precision Farming ◽  
Soil Test ◽  
Strong Basis ◽  
High Productivity ◽  
Basic Parameters

Field experiments were conducted during 2017 – 2018 to develop fertiliser prescriptions equations (FPEs) through IPNS for the desired yield targets of Chrysanthemum on Udic Haplustalf . The fertilisers prescription equations (FPEs) were developed under NPK alone and under IPNS for the desired yield target of Chrysanthemum by using the basic parameters. The variation observed in the achievement of targets was within the range of ± 10 per cent (90 – 110%) proving the validity of FPEs. Hence, the Inductive cum Targeted yield approach applied to develop fertiliser equations provides a strong basis for maintenance of soil fertility with high productivity and efficient nutrient management in “Precision Farming” for sustainable and enduring Agriculture.

scholarly journals Increasing wear resistance of the protective sleeve of the centrifugal pump made of gray cast iron by surface hardening

2021 ◽  
pp. 103
Author(s):  
Nataliia Lalazarova ◽  
Оlga Afanasieva ◽  
Olena Popova ◽  
Oleksiy Dmytrenko
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
High Frequency ◽  
Gray Cast Iron ◽  
Operating Time ◽  
Hardened Layer ◽  
Gray Cast ◽  
Centrifugal Pumps ◽  
Surface Quenching ◽  
Surface Induction

One of the weak spots that reduce the guaranteed operating time of centrifugal pumps is the assembly that includes the seal and protective sleeves. The main purpose of the bushings in the rotor kit is to protect the shaft from corrosion, erosion and wear. The sleeve operates under abrasive wear conditions by packing elements and abrasive particles that get into the liquid pumped by the pump. The protective sleeves made of gray cast iron do not meet the service life in connection with accelerated surface wear. Goal. The purpose of the work is to ensure high wear resistance of cast iron pump parts by heat treatment. Method. The chemical composition was determined on a portable laser analyzer Laser Z200 C +. The structure was studied using an optical microscope. The wear was investigated by the roller-block method on a friction machine. Surface quenching was carried out with a high-frequency lamp generator in a single-turn inductor. Results. The microstructure of gray cast iron as cast consists of pearlite, ferite, double phosphide eutectic and inclusions of lamellar graphite. Microhardness of small-lamellar pearlite is Н50 = 1550–2220 MPa, microhardness of phosphide eutectic is Н50 = 6500–8000 MPa. Surface induction quenching by high-frequency currents followed by low tempering is an effective way to increase the wear resistance of cast iron products of small cross-section and does not cause warping. Cast iron for surface quenching should have a pearlite structure, and graphite should be contained in the form of small inclusions. The optimal heating temperature for induction hardening was determined as 900 °С, which made it possible to obtain the microstructure of the hardened layer – martensite, double phosphide eutectic and graphite. Scientific novelty. The developed modes of surface quenching make it possible to preserve a double phosphide eutectic in the structure of the surface layer, which makes it possible to obtain high hardness and wear resistance of the hardened layer. Practical significance. Surface induction quenching with low tempering of cast gray iron increased its wear resistance by 2,4 times. The previous normalization had practically no effect on the durability of cast iron, since its structure contains less than 10% ferrite.

scholarly journals Promising model range career excavators operating time assessment in real operating conditions

2020 ◽  
Vol 242 ◽  
pp. 228 ◽  
Author(s):  
Sergey IVANOV ◽  
Polina IVANOVA ◽  
Sergey KUVSHINKIN
Keyword(s):  
Good Condition ◽  
Operating Time ◽  
Mining Industry ◽  
Negative Influence ◽  
Technical Condition ◽  
Operating Conditions ◽  
Economic Losses ◽  
Mining Machine ◽  
Mining Equipment ◽  
Detailed Assessment

The development prospects of the mining industry are closely related to the state and development of modern mining machinery and equipment that meet the technical and quality requirements of mining enterprises. Enterprises are focused on a quantitative assessment – the volume of mineral extraction, depending on the functioning efficiency of a promising series of mining machines, which include modern mining excavators. Downtime and unplanned shutdowns of mining excavators directly depend on the operating conditions of the mining machine, which has negative influence on the machine as a whole and its technical condition, which entails a decrease in the efficiency of using expensive mining equipment and economic losses of the mining enterprise. The rationale for external factors that affect the operating time and technical condition of mining excavators is given. For a more detailed assessment of the influence of external influences on the efficiency of operation of mining machines, the influencing factors are divided into two groups: ergatic, directly related to human participation, and factors of a natural-technogenic nature, where human participation is minimized. It was revealed that factors of a natural-technogenic nature have the greatest influence. An algorithm is proposed for a comprehensive assessment of the technical condition and forecasting of operating time both in nominal and in real operating conditions, taking into account factors of a natural and technogenic nature. It is proposed, based on the developed program for planning and evaluating the life of a mining excavator, to adjust the schedules for maintenance and repair (MOT and R) in order to minimize the number of unplanned downtime of a mining excavator and maintain it in good condition.

Optimization of the composition and structure of wear-resistant white cast irons used in the mining industry

2020 ◽  
pp. 4-9
Author(s):  
A. A. Zhumaev ◽  
◽  
Yu. N. Mansurov ◽  
D. D. Mamatkulov ◽  
G. D. Ulugov ◽  
...  
Keyword(s):  
Cast Iron ◽  
Friction And Wear ◽  
White Cast Iron ◽  
Mining Industry ◽  
Machine Building ◽  
Mining Equipment ◽  
Cast Irons ◽  
Wear Resistant ◽  
Building Plant ◽  
Machine Building Plant

The mining industry of Uzbekistan uses hundreds of tons of white wear-resistant cast iron monthly for the manufacture of parts for machinery and equipment that extract natural raw materials. Only the Production Association Navoi Machine-Building Plant (PO «NMZ») monthly produces cast parts from wear-resistant high-chromium alloyed white cast iron with a volume of more than 120 tons per month. Most of the parts are made for rock crushers; their wear during work in mines shortens the service life of machinery and equipment. Parts of foreign equipment: dredge pumps, lining of grinding mills, hydraulic transport and others are made of white cast iron, highly alloyed with chromium, nickel, copper, titanium and other chemical elements. The annual import into the republic of parts made of cast irons of complex chemical composition requires signifi cant costs. In order to save money by refusing to import parts, a domestic wear-resistant white cast iron of grade 280Kh29NL was developed, from which rubbing parts, operating under wear conditions in mines, for mining equipment are cast in the foundry of the Navoi Machine-Building Plant. Considering that ferroalloys for the production of cast iron are also imported, the cost savings in the production of mining equipment parts instead of worn-out ones is insignificant. The purpose of this work is to optimize the composition of highly alloyed wear-resistant white cast iron for its replacement in industry with an economically alloyed analogue, as well as to improve the structure of the composition-optimized white wear-resistant cast iron to obtain the required level of performance properties of parts operating under friction and wear conditions. For this, phase transformations, the structure and properties of white cast iron, and the conditions for casting parts were studied. Based on the research results, recommendations were developed for economical alloying and casting technology for friction and wear parts.

scholarly journals Evaluation of KTT-2 Pneumatic Peat Harvesting Machine’s Nozzle Suction Capacity

2020 ◽  
Vol 174 ◽  
pp. 01044
Author(s):  
Alexander Yablonev ◽  
Darya Scherbakova
Keyword(s):  
Operating Time ◽  
Flow Speed ◽  
Active Area ◽  
Suction Velocity ◽  
High Moor ◽  
Milled Peat ◽  
Basic Parameters ◽  
Suction Flow ◽  
Diagram Analysis ◽  
High Moor Peat

Milled peat harvesting with pneumatic harvesting machines has a number of doubtless advantages over mechanical harvesting: operating time decreases down to 1 day, additional milling of wet peat deposit during the harvesting is not needed, list of necessary machinery decreases. However, in the late 1980s, due to the imperfection of the design of pneumatic machines, this method began to be used less and less frequently. Market appearance of KTT-2 and MPTU-30 pneumatic harvesting machines promoted their introduction into operating processes of peat extractive companies. According to feedback from operators, these machines work well with high-moor peat but work much worse with low- moor peat which is of higher density. One of basic parameters of pneumatic harvesting is suction velocity, that’s why field experiment for evaluation of KTT-2 machine suction nozzle performance was held. Experiment results enabled us to plot velocity diagram of suction flow and find maximum suction velocity: 26.74 m/s. Velocity diagram analysis showed distance from the nozzle – air flow speed relation. We calculated size of suction flow’s active area and offered methods of active area sizing.

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