TECHNICAL CONDITION AND WEAR OF THE LEFT-SIDE KNIVES OF PSKU-SERIES SPEED PLOWS, METHODS OF BRAKING AND WEAR MINIMIZING

2021 ◽  
pp. 56-61
Author(s):  
ALEKSANDR M. MIKHALCHENKOV ◽  
Keyword(s):  
High Speed ◽  
Complex Geometry ◽  
Construction Material ◽  
Technical Condition ◽  
Measuring Instruments ◽  
Low Carbon ◽  
Recovery Method ◽  
Body Design ◽  
Residual Values ◽  
Material Studies

High-speed plowing forces signifi cant changes in the design of the working elements of the plow. Such changes greatly aff ected the wear pattern and, consequently, called for modifi ed technical processes of restoring and strengthening. The working body design includes a plowshare, the function of which is performed by the left-side knife. The research purpose was to control the technical condition of the above-mentioned parts of the PSKu-series plow; study the geometry, location, and magnitude of wear; and develop restoration and hardening technologies. The residual values of thickness and width were used as the criteria for wear since they infl uence the recovery method. These values were controlled by standard measuring instruments – calipers and height gauges. The hardness measured by the Rockwell method (HRC) was used as a criterion for the mechanical properties of the construction material. Studies have shown that the wear on the working surfaces has a rather complex geometry, which is associated with the specifi cs of the force action of the soil. This defect should be eliminated because the probability of extreme wear in thickness increases when the part rotates. The authors proposed that the wear on the left-side knife should be eliminated by patching with a low-carbon electrode and subsequent hardening with surfacing reinforcement. It has been experimentally established that the wear amounts to about 7 mm in thickness and no more than 8 mm in width for a knife with a 45…54 HRC blade. The wear is caused by a hard-facing layer with a hardness of 73…74 HRC on the backside. High-quality heat treatment ensures an increased resistance of the part to abrasive wear. For left-side knives, it is expedient to apply electrode surfacing with a low-carbon rod and the subsequent hardening by surfacing reinforcement.

Geopolymer as a Construction Material in Low-carbon and Resource Recycling Society

2019 ◽  
Vol 57 (1) ◽  
pp. 91-93
Author(s):  
K. Minami ◽  
K. Ohta ◽  
M. Funahashi ◽  
H. Kajita
Keyword(s):  
Construction Material ◽  
Low Carbon ◽  
Resource Recycling ◽  
Recycling Society

scholarly journals Does the Opening of High-Speed Railway Lines Reduce the Carbon Intensity of China’s Resource-Based Cities?

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4648
Author(s):  
Zhipeng Tang ◽  
Ziao Mei ◽  
Jialing Zou
Keyword(s):  
High Speed ◽  
National Average ◽  
Carbon Intensity ◽  
Time Varying ◽  
Low Carbon ◽  
High Speed Railway ◽  
Different Types ◽  
Endogenous Selection ◽  
Mode Of Development ◽  
The Impact

The carbon intensity of China’s resource-based cities (RBCs) is much higher than the national average due to their relatively intensive mode of development. Low carbon transformation of RBCs is an important way to achieve the goal of reaching the carbon emissions peak in 2030. Based on the panel data from 116 RBCs in China from 2003 to 2018, this study takes the opening of high-speed railway (HSR) lines as a quasi-experiment, using a time-varying difference-in-difference (DID) model to empirically evaluate the impact of an HSR line on reducing the carbon intensity of RBCs. The results show that the opening of an HSR line can reduce the carbon intensity of RBCs, and this was still true after considering the possibility of problems with endogenous selection bias and after applying the relevant robustness tests. The opening of an HSR line is found to have a significant reducing effect on the carbon intensity of different types of RBC, and the decline in the carbon intensity of coal-based cities is found to be the greatest. Promoting migration of RBCs with HSR lines is found to be an effective intermediary way of reducing their carbon intensity.

Aluminum nitride buffer layer for diamond film growth

1996 ◽  
Vol 11 (7) ◽  
pp. 1810-1818 ◽  
Author(s):  
V. P. Godbole ◽  
J. Narayan
Keyword(s):  
Aluminum Nitride ◽  
Buffer Layer ◽  
Diamond Film ◽  
High Speed ◽  
Film Growth ◽  
High Speed Steel ◽  
Bearing Steel ◽  
Low Carbon ◽  
Wide Range ◽  
Steel Substrates

The role of aluminum nitride (AlN) as a buffer layer on the nucleation and growth of diamond on silicon and steel substrates during hot filament chemical vapor deposition (HF-CVD) has been investigated systematically. The scanning Auger electron microscopy (AES) is employed to study chemistry and content of carbon on the surface and in subsurface regions of AlN as a function of HF-CVD parameters. It is found that AlN offers an excellent diffusion barrier for carbon over a wide range of temperature and hydrocarbon content of CVD gas environment, with simultaneous inhibition of graphitization. It also facilitates nucleation of diamond phase. The surface reactions between AlN and carbon are discussed in terms of hydrogen-assisted phase transformations. We have developed a two-step procedure to obtain a continuous diamond film on steel substrates. The characteristic features of AlN have been exploited to obtain adherent and graphite-free diamond deposits on various types of steels, including low carbon steel, tool steel, high speed steel, and bearing steel.

Recovery of Waste Leather From Tanneries as Aggregate in Composite Materials

2020 ◽  
Vol 65 (2) ◽  
pp. 39-55
Author(s):  
Gabriela-Emilia Popița ◽  
◽  
Cristina Roșu ◽  
Dorin Manciula ◽  
Ofelia Corbu ◽  
...  
Keyword(s):  
Composite Material ◽  
Construction Material ◽  
Mechanical Tests ◽  
Economic Benefits ◽  
Cement Matrix ◽  
Production Flow ◽  
Total Chromium ◽  
Glass Waste ◽  
Recovery Method ◽  
Leather Waste

This study proposes a recovery method for waste leather from tanneries, with high chromium content, by incorporating it into a composite material with cement matrix. The natural aggregates were substituted with CRT (cathode ray tubes) glass waste, with high lead content, originated from televisions and monitors dismantling. The material technological production flow was as follows: grinding skin (two types of skin: black and brown were used), mixing the ingredients after own recipes, pouring the mixture into molds, maturation, demoulding. The new material obtained was submitted to leachability tests to determine, using AAS (Atomic Absorption Spectrometry), the total chromium and lead concentration released from the material. The results showed that Cr and Pb were well retained in the cement matrix. The low levels of total Cr and Pb concentration were recorded at pH = 9-10 and pH = 12, for the composite containing black leather waste and and at pH = 2-3 and pH = 12 for the composite containing brown leather waste. Mechanical tests were also provided to evidence the mechanical properties of the composite. The new composite material obtained may be considered as construction material and can be classified in mortars class because of the size of the used aggregate (CRT glass waste). The objective of this study was to obtain a composite material that can be used as material for construction, in compliance with current standards in construction and environmental legislation. The proposed method for leather waste recovery is viable and environmentally friendly and could bring economic benefits. Keywords: leather, waste, CRT, composite, material.

Velocity and Volume Fraction Measurements of Granular Flows in a Steep Flume

2021 ◽  
Author(s):  
Luca Sarno ◽  
Maria Nicolina Papa ◽  
Luigi Carleo ◽  
Paolo Villani
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Granular Flows ◽  
Indirect Measurement ◽  
Measuring Instruments ◽  
Second Order Statistics ◽  
Granular Dynamics ◽  
Image Velocimetry ◽  
Near Wall

ABSTRACT Laboratory experiments on granular flows remain essential tools for gaining insight into several aspects of granular dynamics that are inaccessible from field-scale investigations. Here, we report an experimental campaign on steady dry granular flows in a flume with inclination of 35°. Different flow rates are investigated by adjusting an inflow gate, while various kinematic boundary conditions are observed by varying the basal roughness. The flume is instrumented with high-speed cameras and a no-flicker LED lamp to get reliable particle image velocimetry measurements in terms of both time averages and second-order statistics (i.e., granular temperature). The same measuring instruments are also used to obtain concurrent estimations of the solid volume fraction at the sidewall by employing the stochastic-optical method (SOM). This innovative approach uses a measurable quantity, called two-dimensional volume fraction, which is correlated with the near-wall volume fraction and is obtainable from digital images under controlled illumination conditions. The knowledge of this quantity allows the indirect measurement of the near-wall volume fraction thanks to a stochastic transfer function previously obtained from numerical simulations of distributions of randomly dispersed spheres. The combined measurements of velocity and volume fraction allow a better understanding of the flow dynamics and reveal the superposition of different flow regimes along the flow depth, where frictional and collisional mechanisms exhibit varying relative magnitudes.

Effect Of The Rib Inclination Angle On Liquid Film Spreading Over The Structured Surface

2015 ◽  
Vol 10 (1) ◽  
pp. 42-49
Author(s):  
Aleksandr Pavlenko ◽  
Oleg Volodin ◽  
Vladimir Serdyukov
Keyword(s):  
Liquid Film ◽  
Flow Rate ◽  
Inclination Angle ◽  
High Speed ◽  
Film Flow ◽  
Complex Geometry ◽  
Experimental Studies ◽  
Local Flow ◽  
Structured Packing ◽  
Film Spreading

Results of experimental studies on hydrodynamics of the film flow of liquid nitrogen over the surface of the single elements of structured packing are presented. The effect of inclination angle of the large ribs and perforation on the zones of liquid film spreading over the corrugated surface with microtexture at different Reynolds numbers of the film is shown based on a comparison of experimental data. It is shown that the angle of large rib inclination has a significant influence on redistribution of the local flow rate of liquid flowing on the surface with complex geometry. Analysis of results of the high-speed video revealed that in a vicinity of the vertical lateral edges of corrugated plates, the intense rivulet flows are formed, including those with separation from the film flow surface. This negative factor can lead to significant liquid accumulation and flow near the vertical edges of the structured packing and on the inner wall of the heat exchanging apparatuses and, finally, to a significant increase in the degree of maldistribution of local liquid flow rate over the crosssection, for instance, of the distillation columns.

scholarly journals Step-by-step control of target efficiency indices of the control and measuring equipment stock applied in construction and housing and communal services

2018 ◽  
Vol 170 ◽  
pp. 01010 ◽  
Author(s):  
Rustam Khayrullin ◽  
Pavel Ivanov
Keyword(s):  
Mathematical Model ◽  
Finite Difference ◽  
Measuring Equipment ◽  
Technical Condition ◽  
Measuring Instruments ◽  
Finite Difference Equations ◽  
Target Values ◽  
The Mathematical Model ◽  
Step Control ◽  
Different Levels

The mathematical model is considered for the formation and implementation of development strategies of the stock of control and measuring instruments (CMI) applied in construction and housing and communal services(HCS), and step-by-step control of efficiency target values of the stock. The model is based on a system of finite - difference equations describing the change of number of the CMI samples with different levels of technical perfection and technical condition at each planning interval. The model allows calculating the required number of CMI for procurement and repairs in the various groups for provide target values of efficiency indices at each planning interval. Controller is number of modern CMI samples for procurement and number of modern and obsolete faulty CMI samples for the repairs. The results of calculations are presented.

scholarly journals PENGGUNAAN STEEL GRIT G25 PADA SANDBLASTING BAJA KARBON RENDAH JIS-G3101-SS400

2019 ◽  
Vol 17 (3) ◽  
Author(s):  
Muslimin Muslimin ◽  
Azam Milah Muhamad
Keyword(s):  
Surface Quality ◽  
Coating Thickness ◽  
Construction Material ◽  
Low Carbon Steel ◽  
Process Time ◽  
Material Surface ◽  
Low Carbon ◽  
Abrasive Material ◽  
Abrasive Particles ◽  
Fixed Parameter

ABSTRACTSandblasting is an abrasive particles shooting to material surface for cleaning dust, paint, and rust, along as increasing material surface structure quality for coating, painting and other adhesive process. Al2O3 and steel grit are the most abrasive particles used in this process. Al2O3 is reusable particle inspite of more expensive and producing more dust. On the other hand, steel grit is cheaper and producing less dust. This article focuses on the use of the new and the reused steel grit G25 in sandblasting process of construction material low carbon steel. The objective is to study the effect of the new and reused abrasive material steel grit in sandblasting process on the surface quality. The methods of this experiments are comparing the surface quality of sandblasting process of new and once reused steel grit G25 using the same experimental parameters. Fixed parameter in this experiment is the nozzle pressure, 5 bar, while the independent variables are process distance (15 cm, 25 cm, and 30 cm) and the process time (25 s, 45 s, 120 s). Testing analyses in this experiments are roughness test ASTM D7127-13 and coating thickness test ASTM D-7091. Result of the experiment are coating thickness result are the highest 120 μm and the least 94,14 μm for the new steel grit, while 89,88 μm and 58,58 μm the highest and least for the once used steel grit. Highest roughness result for the new steel grit are 21,4 μm and once used steel grit 17,8 μm, while the least rough are 18,1 μm for the new steel grit and 3, 452 μm for once used steel grit. The once used steel grit G25 still can be accepted as abrasive material in sandblasting process but with less good quality than the new one.Key words :sandblasting, new steel grit G25, new steel grit G25, surface roughness.ABSTRAKSandblasting adalah suatu proses penembakan partikel abrasif ke suatu permukaan untuk membersihkan debu, cat, dan karat, dan membuat tekstur permukaan material agar lapisan pelindung dapat menempel lebih baik. Partikel abrasif yang banyak digunakan dalam proses sandblasting adalah Al2O3 dan steel grit. Partikel Al2O3 memiliki ketahanan abrasive yang tinggi, tetapi harganya lebih mahal dan menghasilkan debu proses lebih banyak. Sedangkan, steel grit harganya lebih murah dan sedikit menghasilkan debu proses. Penelitian ini berfokus pada penggunaan material abrasif steel grit G25 baru dan pemakaian ulang untuk proses sandblasting baja karbon rendah untuk material konstruksi. Tujuan penelitian ini adalah mengkaji pengaruh penggunaan steel grit G25 dan penggunaan ulangnya terhadap kualitas permukaan hasil sandblasting.Metode yang digunakan, yaitu dengan membandingkan hasil proses sandblasting dengan partikel steel grit G25 baru dan partikel steel grit G25 pemakaian ulang (1 kali pemakaian) dalam parameter uji yang sama. Parameter tetap yang digunakan yaitu tekanan nozzle sebesar 5 bar, sedangkan variabel bebasnya yaitu jarak (15 cm, 25 cm, dan 30 cm) dan waktu penembakkan (25 detik, 45 detik, dan 120 detik). Analisis pengujian yang digunakan adalah uji kekasaran ASTM D7127-13 dan uji ketebalan cat ASTM D7091. Nilai ketebalan cat tertinggi steel grit baru 120 μm, steel grit ulang 89,88 μm, dan terendah steel grit baru 94,14 μm, steel grit ulang 58,58 μm. Nilai kekasaran tertinggi steel grit baru 21,4 μm, steel grit ulang 17,8 μm, dan terendah steel grit baru 18,1 μm, steel grit ulang 3,452 μm. Penggunaan steel grit G25 penggunaan baru lebih baik dibandingkan dengan penggunaan ulangnya, dengan hasil pengujian steel grit baru yang lebih tinggi dengan penggunaan ulang.Katakunsi : sandblasting, steel grit G25 baru, Steel grit G25 sekali pakai, kekasaran permukaan.

SYSTEM OF STANDARDIZATION AND METROLOGICAL SUPPORT OF SPEED DEFECTIVE MEANS OF RAILS IN THEIR PRODUCTION AND OPERATION

2021 ◽  
pp. 14-29
Author(s):  
V. F. Tarabrin
Keyword(s):  
Metrological Support ◽  
High Speed ◽  
Dynamic Testing ◽  
Flaw Detection ◽  
Measuring Instruments ◽  
High Speed Rail ◽  
Technical Control ◽  
Instrument Control ◽  
Factory Testing ◽  
Production And Operation

The importance of standardization and metrological support for high-speed rail flaw detection is noted. JSC “Firm TVEMA” has created a service for quality, factory testing and metrological support. The data on the development and development of the production of JSC “Firma TVEMA” of a complex of removable and mobile technical means of NDT with maximum automation of instrument control and processing of control data, creation of a quality service, factory testing and metrological support are given. It is shown that the service includes structural subdivisions: the department of metrology and quality, a metrological laboratory, a testing laboratory, a technical control bureau that provide scientific and methodological support for the development of measuring instruments, testing, verification and calibration of flaw detection instruments during their production and operation. JSC “Firma TVEMA” organized the production and delivery of models of rail defects to railways with primary certification by the metrological laboratory for dynamic testing of mobile NDT vehicles. A test section was put into operation at the Experimental Ring of JSC VNIIZhT with certified defect models, which made it possible to accumulate research material for the further development of high-speed flaw detectors.

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