scholarly journals Assessment of the Impact of Atmospheric Corrosivity on the Cement Concrete Airfield Pavement’s Operation Process

2020 ◽  
Vol 12 (22) ◽  
pp. 9560
Author(s):  
Mariusz Wesolowski ◽  
Aleksandra Rumak ◽  
Pawel Iwanowski ◽  
Adam Poswiata
Keyword(s):  
Low Carbon Steel ◽  
Technical Condition ◽  
Low Carbon ◽  
Atmospheric Conditions ◽  
Cement Concrete ◽  
Standard Samples ◽  
Functional Elements ◽  
Operation Process ◽  
Constant State ◽  
The Impact

The aim of this research is to assess corrosion in natural atmospheric conditions, based on exposure of material samples and periodic monitoring, and to determine the size of corrosion losses, their form and appearance, as well as changes in physical properties at regular time intervals. Atmospheric corrosion tests were ultimately carried out in order to determine the corrosion resistance of a cement concrete airfield pavement, as well as to assess the type of corrosion and research data in order to determine and estimate the corrosivity of the atmosphere. Atmospheric corrosivity is one of the parameters characterizing the technical condition of airfield pavement functional elements; it makes it possible to estimate a suitable frequency of airfield periodic inspections. Assessments of concrete corrosion and atmospheric corrosivity enable appropriate countermeasures to be taken in order to maintain the airport functional elements in a constant state of technical readiness. In the following study, the prepared samples were exposed to atmospheric conditions in designated places located at selected military airport facilities. Corrosion samples in the form of 50 mm × 100 mm standard samples, 1 mm to 3 mm in thickness, were placed on special frames located within fenced corrosion stations. The corrosion rate rcorr of a specific metal, expressed as a corrosion loss, depends on the environmental conditions. This article presents an atmosphere corrosivity category assessment for low-carbon steel, zinc, copper and aluminum reference samples, taking into account weight or thickness loss after one year of exposure.

Multi-Criteria Analysis in Assessment of the Degree of Degradation Pavement Elements Functional Airports Made of Cement Concrete

2017 ◽  
Author(s):  
Mariusz Wesołowski ◽  
Krzysztof Blacha ◽  
Piotr Barszcz
Keyword(s):  
Quality Management System ◽  
Technical Condition ◽  
Cement Concrete ◽  
Functional Elements ◽  
Surface Degradation ◽  
Visual Method ◽  
Flight Operations ◽  
Multi Criteria Analysis ◽  
Degree Of Degradation

An important factor that affects the safety of flight operations is the proper management of airports, which should be based on the obtained in systematic way information about the state of the surface of the functional elements. One of the characteristic quantities of the technical condition of airport indicator is the assessment of the degree of degradation. It should be noted that the degradation is a slow process extended in time and is the lowering of the properties of the structure by external influences, which in turn generates the changes in their structure. Rating degrade surface should be conducted periodically, which period shall be estimated on the basis of information obtained from the process of the operation of aircraft. Demotions surface is determined on the basis of the type and quantity survey found damage and made repairs. The basis for evaluating the degree of surface degradation is to obtain data from surveys conducted using the method of visual and inventory of them. Research by visual method, despite its apparent simplicity, it is difficult to implement. Qualification of damage or repairs to the appropriate group is often not clear, and therefore the inventory process is described in the documentation of quality management system. The multi-criteria analysis is a method of evaluating the weighted supporting estimating the degree of degradation airfield pavements based on data obtained through inspections performed. Its base is included in the determination of a number of criteria for the selection variant, taking into account different weights to each criterion. The value of the indicator characterizing the degree of surface degradation in relation to estimated criteria allows you to schedule the necessary resources needed to carry out repairs and rational planning of repairs.

Effects of Al, Si and N Content on the Formation of M-A Constituent and HAZ Toughness of Ti-Containing Low-Carbon Steel

2021 ◽  
Vol 1016 ◽  
pp. 42-49
Author(s):  
Kook Soo Bang ◽  
Joo Hyeon Cha ◽  
Kyu Tae Han ◽  
Hong Chul Jeong
Keyword(s):  
Carbon Steel ◽  
Impact Toughness ◽  
Low Carbon Steel ◽  
Charpy Impact ◽  
Coarse Grained ◽  
Low Carbon ◽  
N Content ◽  
Si Content ◽  
The Impact ◽  
Haz Toughness

The present work investigated the effects of Al, Si, and N content on the impact toughness of the coarse-grained heat-affected zone (CGHAZ) of Ti-containing low-carbon steel. Simulated CGHAZ of differing Al, Si, and N contents were prepared, and Charpy impact toughness was determined. The results were interpreted in terms of microstructure, especially martensite-austenite (M-A) constituent. All elements accelerated ferrite transformation in CGHAZ but at the same time increased the amount of M-A constituent, thereby deteriorating CGHAZ toughness. It is believed that Al, Si, and free N that is uncombined with Ti retard the decomposition of austenite into pearlite and increase the carbon content in the last transforming austenite, thus increasing the amount of M-A constituent. Regardless of the amount of ferrite in CGHAZ, its toughness decreased linearly with an increase of M-A constituent in this experiment, indicating that HAZ toughness is predominantly affected by the presence of M-A constituent. When a comparison of the effectiveness is made between Al and Si, it showed that a decrease in Si content is more effective in reducing M-A constituents.

Effect of Ti, Al and Mg Addition on the Impact Toughness of Heat Affected Zone in Low Carbon Steel

2009 ◽  
Vol 79-82 ◽  
pp. 143-146
Author(s):  
Jiang Hua Ma ◽  
Dong Ping Zhan ◽  
Zhou Hua Jiang ◽  
Ji Cheng He
Keyword(s):  
Carbon Steel ◽  
Impact Toughness ◽  
Heat Affected Zone ◽  
Low Carbon Steel ◽  
Optical Microscope ◽  
Carbon Steels ◽  
Low Carbon ◽  
Welding Simulation ◽  
Mg Addition ◽  
The Impact

In order to understand the effects of deoxidizer such as aluminium, titanium and magnesium on the impact toughness of heat affected zone (HAZ), three low carbon steels deoxidized by Ti-Al, Mg and Ti-Mg were obtained. After smelting, forging, rolling and welding simulation, the effects of Al, Ti and Mg addition on the impact toughness of HAZ in low carbon steel were studied. The inclusion characteristics (size, morphology and chemistry) of samples before welding and the fracture pattern of the specimens after the Charpy-type test were respectively analyzed using optical microscope and scanning electron microscopy (SEM). The following results were found. The density of inclusion in Ti-Mg deoxidized steel is bigger than Ti-Al deoxidized steel. The average diameter is decreased for the former than the latter. The addition of Ti-Mg can enhance the impact toughness of the HAZ after welding simulation. The maximal value of the impact toughness is 66.5J/cm2. The complex particles of MgO-TiOx-SiO2-MnS are most benefit to enhance impact toughness. The improvement of HAZ is attributable to the role of particle pinning and the formation of intergranular ferrite.

scholarly journals The impact of exploitation and environmental factors on the degradation of steel road safety equipment

2018 ◽  
Vol 231 ◽  
pp. 01012
Author(s):  
Joanna Kobus ◽  
Lech Kwiatkowski ◽  
Rafał Lutze
Keyword(s):  
Road Safety ◽  
Zinc Coating ◽  
Low Carbon Steel ◽  
Environmental Parameters ◽  
Galvanized Steel ◽  
Traffic Intensity ◽  
Low Carbon ◽  
Zinc Corrosion ◽  
The Impact

The work is aimed at determining the corrosivity of atmosphere in the vicinity of roads, taking into account the characteristics of local emission sources, including traffic intensity of vehicles along with climatic and exploitation factors. Determination of the corrosivity of atmosphere was carried out according to the procedures described in PN EN ISO standards. Samples for testing were made of low carbon steel DC05, zinc and hot dip galvanized steel. Samples were assembled at 19 sites in the close vicinity of roads and highways near the measurement points of vehicle traffic intensity. The mass loss of exposed samples was the basis for determination the atmosphere corrosivity at each of 19 test sites. Regarding steel, the corrosivity category of C4 was observed at 8/19 sites. Corrosion losses outside roads are 2-4 times lower and ranged within the categories of C2 and C3. Zinc corrosion losses classified to category C4 occurred at 2/19 stations. In the remaining ones they corresponded to category C3. In areas outside of roads, zinc corrosion losses are about 20-100% lower (C2). The first attempts to model the dependence of operating and environmental parameters on zinc and zinc coating corrosion losses indicate significant correlation between zinc and zinc coating corrosion losses as a function.

scholarly journals Microstructure and mechanical characteristics of hot forged lateritic steels

2018 ◽  
Vol 204 ◽  
pp. 05007 ◽  
Author(s):  
Satrio Herbirowo ◽  
Luqmanul Hakim ◽  
Bintang Adjiantoro
Keyword(s):  
Raw Materials ◽  
Hot Forging ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Cast Steels ◽  
Preheating Temperature ◽  
Chemical Composition Of Steel ◽  
Forging Force ◽  
The Impact ◽  
Hot Forging Process

The current development of steel industry has constraints on the availability of raw materials, so we have developed local raw materials that are lateritic steels as a high potential for alternative manufacturing of steel. This research was conducted to understand the characteristics of lateritic steel through hot forging process by the mechanical and microstructure behaviour. The research methodology was chained by variety of preheating temperature of 800; 1000; 1200 °C and forging force from 0 until 1000 kilonewton. In case of hot forging values was obtained the impact and hardness properties also microstructure that compared with as-cast steels. The results of impact strength increased by 81.83% at the temperature of 1200 °C and the hardness increased by 4.99% at 1000 °C, for the microstructure analysis was produced the ferrite and pearlite phases with the fine grains. The chemical composition of steel is classified in low carbon steel included in lateritic steel it contains low alloy 1.78 Ni and 0.553 Cr %wt.

scholarly journals Effect of Carbon Partitioning, Carbide Precipitation, and Grain Size on Brittle Fracture of Ultra-High-Strength, Low-Carbon Steel after Welding by a Quenching and Partitioning Process

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 747 ◽  
Author(s):  
Farnoosh Forouzan ◽  
M. Guitar ◽  
Esa Vuorinen ◽  
Frank Mücklich
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Weld Zone ◽  
Low Carbon Steel ◽  
High Strength ◽  
Precipitate Size ◽  
Low Carbon ◽  
Quenching And Partitioning ◽  
High Level ◽  
The Impact

To improve the weld zone properties of Advanced High Strength Steel (AHSS), quenching and partitioning (Q&P) has been used immediately after laser welding of a low-carbon steel. However, the mechanical properties can be affected for several reasons: (i) The carbon content and amount of retained austenite, bainite, and fresh martensite; (ii) Precipitate size and distribution; (iii) Grain size. In this work, carbon movements during the partitioning stage and prediction of Ti (C, N), and MoC precipitation at different partitioning temperatures have been simulated by using Thermocalc, Dictra, and TC-PRISMA. Verification and comparison of the experimental results were performed by optical microscopy, X-ray diffraction (XRD), Scanning Electron Microscop (SEM), and Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) and Electron Backscatter Scanning Diffraction (EBSD) analysis were used to investigate the effect of martensitic/bainitic packet size. Results show that the increase in the number density of small precipitates in the sample partitioned at 640 °C compensates for the increase in crystallographic packets size. The strength and ductility values are kept at a high level, but the impact toughness will decrease considerably.

scholarly journals Modified Manganese Phosphate Conversion Coating on Low-Carbon Steel

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1416
Author(s):  
Jakub Duszczyk ◽  
Katarzyna Siuzdak ◽  
Tomasz Klimczuk ◽  
Judyta Strychalska-Nowak ◽  
Adriana Zaleska-Medynska
Keyword(s):  
Low Carbon Steel ◽  
Microscopic Analysis ◽  
Metal Cations ◽  
Steel Structures ◽  
Xrd Analysis ◽  
Low Carbon ◽  
Destructive Effect ◽  
Electrochemical Tests ◽  
Manganese Phosphate ◽  
The Impact

Conversion coatings are one of the primary types of galvanic coatings used to protect steel structures against corrosion. They are created through chemical reactions between the metal surface and the environment of the phosphating. This paper investigates the impact that the addition of new metal cations to the phosphating reaction environment has on the quality of the final coating. So far, standard phosphate coatings have contained only one primary element, such as zinc in the case of zinc coatings, or two elements, such as manganese and iron in the case of manganese coatings. The structural properties have been determined using a scanning electron microscope (SEM), X-ray diffraction (XRD), and electrochemical tests. New manganese coatings were produced through a reaction between the modified phosphating bath and the metal (Ba, Zn, Cd, Mo, Cu, Ce, Sr, and Ca). This change was noticeable in the structure of the produced manganese phosphate crystallites. A destructive effect of molybdenum and chromium was demonstrated. Microscopic analysis, XRD analysis and electrochemical tests suggest that the addition of new metal cations to the phosphating bath affects the corrosion resistance of the modified coating.

scholarly journals The Influence of the Angle of the Working Part of the Die on the High Speed Drawing Process of Low Carbon Steel Wires

2017 ◽  
Vol 62 (2) ◽  
pp. 483-487 ◽  
Author(s):  
M. Suliga ◽  
R. Wartacz ◽  
J. Michalczyk
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Experimental Studies ◽  
Low Carbon Steel ◽  
Drawing Process ◽  
Low Carbon ◽  
Wire Rod ◽  
Steel Wires ◽  
Drawing Angle ◽  
The Impact

Abstract The paper contains the theoretical and experimental analysis of the impact of the drawing angle on the drawing process and the properties of low carbon steel wires. A multi-stage drawing wire rod with a diameter of 5.5 mm on a wire with a diameter of 1.0 mm has been carried out in two stages. The first one consisted of preliminary drawing wire rod for the wire with a diameter of 2.2 mm which was next subjected to the drawing process at a speed of 25 m/sec at the final wire with a diameter of 1.0 mm. The wires were drawn in conventional dies with drawing angle α = 3, 4, 5, 6, 7 degrees. For the wires drawn in respective variants, the investigation of the mechanical properties was performed and the amount of lubricant on the surface of steel wires was determined. Numerical analysis of the process of drawing in the Drawing 2D complemented the experimental studies. It has been shown that when drawing at high speeds, properly chosen the value of the angle of the working part of the die can improve the lubrication conditions and mechanical properties of steel wires.

Experimental Analysis of an Instrumented Charpy Impact Using Signal Processing Approach

2011 ◽  
Vol 197-198 ◽  
pp. 1621-1625
Author(s):  
Mohd Basri Ali ◽  
Shahrum Abdullah ◽  
M.Zaki Nuawi ◽  
M.M. Padzi ◽  
K.A. Zakaria
Keyword(s):  
Signal Processing ◽  
Data Acquisition ◽  
Method Comparison ◽  
Low Carbon Steel ◽  
Charpy Impact ◽  
Dynamic Responses ◽  
Low Carbon ◽  
Impact Machine ◽  
Processing Approach ◽  
The Impact

The dynamic responses of the standard charpy impact machine are experimentally studied using the relevant data acquisition system in order to obtain the impact response. For this reason, strain gauges were connected to the data acquisition set and it was then attached to the charpy striker for the signal collection. Aluminium 6061 and low carbon steel 1050 were used for extracting strain responses on the striker during the testing. In this work, the power spectrum density (PSD) approach was then used for the energy based observation and a signal was converted from the time domain to the frequency domain using the fast Fourier transform (FFT) method. Comparison between experimental findings with related parameters such as of different materials, strain signals pattern, I-kaz, were finally correlated and discussed. It was found that the modulus of elasticity were proportional to the energy absorbed, strain signals amplitude and PSD. Finally, it is suggested that the properties of materials and the impact signals pattern is suitable to be analysed using the signal processing approach.

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