Dependence of a Lüders band propagation rate and Lüders elongation on model parameters in a low carbon steel sample

2020 ◽  
Author(s):  
A. O. Chirkov
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Propagation Rate ◽  
Steel Sample ◽  
Model Parameters ◽  
Low Carbon ◽  
Lüders Band ◽  
Carbon Steel Sample

scholarly journals Prediction of the Emissivity Curve at High Temperatures of Low Carbon Steel

2020 ◽  
Vol 9 (2) ◽  
pp. 59
Author(s):  
Vinicius Santos de Deus ◽  
José Adilson de Castro ◽  
Sandro Rosa Rosa Corrêa
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Experimental Methodology ◽  
Continuous Annealing ◽  
Model Parameters ◽  
Sigmoid Function ◽  
Low Carbon ◽  
Surface Emissivity ◽  
Effective Emissivity ◽  
Welding Processes

The thermography is an attractive technique to record the real-time temperature during the continuous welding processes. The temperature distribution during the weld zone is essential for understanding and evaluating the metallurgical properties of the joints. The knowledge of the material emissivity curve is necessary for the precise acquisition of thermography data. This emissivity value is usually assumed constant in the thermography software data acquisition, resulting in inaccurate thermographic data. The surface emissivity usually depends on the temperature. Thus, the values obtained in the literature may not be valid for materials of interest under the process’s conditions. Especially in the case of the low carbon steels, the emissivity data available are scarce and frequently obtained at low temperatures (below 200oC). Therefore, we proposed a methodological procedure to measure the effective surface emissivity, which considers the effect of temperatures and surface conditions. This research was focused on the development of an experimental methodology for determining the emissivity curve, using as the sample, a low carbon steel (0.07% C) with 0.21 mm thickness obtained from the productive stock of a continuous annealing line in the steel plant of the Companhia Siderúrgica Nacional (CSN). The normal sample emissivity was evaluated in the temperature range from 100ºC to 800ºC. It was proposed a model based on a sigmoid function to represent the effective emissivity during temperature rise. The sigmoid model parameters were obtained by a fitting procedure using temperature measurements obtained by thermocouples. The results showed an effective emissivity variation as a function of temperature, where emissivity values raged in the interval of 0.09 to 0.83. Thus, the useful emissivity curve was used to correct the thermography data obtained in electrical resistance seam welding (RSEW) with three levels of heats inputs. The correlation for the emissivity curve incorporated in the thermography software was applied to the thermal profiles of the welds analyzed from 441ºC to 713ºC. These values are consistent with the welding process used. The developed methodology can be applied, in a similar way, in the correction of profiles in other types of welding processes.

Effect of Electrolytic-Plasma Carbonitriding on Structure and Microhardness of Low Carbon Steel 18CrNi3Mo

2013 ◽  
Vol 379 ◽  
pp. 101-104
Author(s):  
Mazhyn Skakov ◽  
Lyaila Bayatanova ◽  
Michael Sсheffler
Keyword(s):  
Carbon Steel ◽  
Structure Formation ◽  
Layer Structure ◽  
Low Carbon Steel ◽  
Steel Sample ◽  
Strength Properties ◽  
Low Carbon ◽  
Gradient Layer ◽  
Modified Layer

In this paper modified gradient layer was under research, the resulting electrolytic-plasma carbonitriding of low carbon steel 18CrNi3Mo surface was investigated. Aiming to improve the structure and strength properties of the layer, the possibility of application have been shown. Plasma carbonitriding optimized mode is presented as well. Regime of electrolyte plasma carbonitriding which consists in heating the steel sample to 8500C with aggregate exposure at this temperature for 3-7 min. and quenching in cold electrolyte has been optimized. We studied the processes of modified layer structure formation under different conditions

Effect of Alloying Elements on the Corrosion Behavior of Carbon Steel in CO2 Environments

CORROSION ◽  
10.5006/2705 ◽  
2018 ◽  
Vol 74 (5) ◽  
pp. 566-576 ◽  
Author(s):  
Yoon-Seok Choi ◽  
Srdjan Nešić ◽  
Hwan-Gyo Jung
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Low Carbon Steel ◽  
Steel Sample ◽  
Alloying Elements ◽  
Low Carbon ◽  
Surface Analysis Techniques ◽  
Positive Effect ◽  
Effect Of Alloying

The objective of the present study was to evaluate the effect of alloying elements (Cr, Mo, and Cu) on the corrosion behavior of low carbon steel in CO2 environments. Six samples were prepared with varying Cr content from 0 wt% to 2 wt% and with added 0.5 wt% of Mo and Cu; the specimens had ferritic/pearlitic microstructures. Steel samples were exposed to a CO2-saturated 1 wt% NaCl solution with different combinations of pH and temperature (pH 4.0 at 25°C, pH 6.6 at 80°C, and pH 5.9 at 70°C). Changes in corrosion rate with time were determined by linear polarization resistance measurements. The surface morphology and the composition of the corrosion product layers were analyzed by surface analysis techniques (scanning electron microscopy and energy dispersive x-ray spectroscopy). Results showed that the presence of Cr and Cu showed a slight positive effect on the corrosion resistance at pH 4.0 and 25°C. At pH 6.6 and 80°C, regardless of the alloying elements, the trend of corrosion rate with time was similar, i.e., the corrosion rate of all specimens decreased with time resulting from the formation of protective FeCO3. A beneficial effect of Cr presence was clearly seen at “gray zone” conditions: pH 5.9 and 70°C, where steel sample without Cr showed no decrease in corrosion rate with time. The presence of Cr in the steel promoted the formation of protective FeCO3 with Cr enrichment and it decreased the corrosion rate.

scholarly journals Karakterisasi Ketahanan Lelah Takik Ulir Whitworth Akibat Pembebanan Puntir Dinamis pada Baja Karbon Rendah

2020 ◽  
Vol 5 (2) ◽  
pp. 154-162
Author(s):  
A Hasan Atho’ullah ◽  
Heri Yudiono
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Initial Crack ◽  
Group Comparison ◽  
Low Carbon ◽  
Notch Depth ◽  
Intact Group ◽  
Dynamic Torsion

This study aims to analyze Whitworth thread's fatigue characterization due to dynamic twisting on low carbon steel. The research method uses experiments with pre-experimental design with the form of intact group comparison. The experimental group was specimens with Whitworth thread notch depth of 0.67 mm, 0.81 mm, and 1.16 mm. The control group was Whitworth threads with a notch depth of 0.9 mm. The study used low carbon steel with a carbon content of 0.12% wt. The dynamic torsion testing with a twisting angle of 5 reveals that the deeper the Whitworth thread notch, the lower the fatigue resistance. The fracture surface is visible due to dynamic torsion in the form of initial crack, crack propagation rate, and final crack.Fenomena kegagalan lelah disebabkan oleh pola pembebanan dan bentuk takikan. Pola pembebanan terjadi karena puntir lentur dan puntir dinamis. Bentuk takikan diperlukan karena tuntutan desain, salah satunya adalah takik ulir whitworth. Penelitian ini bertujuan untuk menganalisis karakterisasi ketahanan lelah ulir whitworth akibat pembebanan puntir dinamis pada baja karbon rendah. Metode penelitian menggunakan eksperimen dengan pre-experimental design dengan bentuk intact-group comparison. Kelompok eksperimen adalah spesimen dengan kedalaman takik ulir whitworth 0.67 mm, 0.81 mm, dan 1.16 mm. Kelompok kontrol dengan kedalaman takik ulir whitworth sebesar  0.9 mm. Penelitian menggunakan baja karbon rendah dengan kandungan karbon sebesar 0.12% wt. Hasil pengujian puntir dinamis mengungkapkan bahwa semakin dalam takik ulir withworth maka ketahanan lelahnya semakin menurun. Bentuk penampang patah akibat pembebanan puntir dinamis berupa initial crack, crack propagation rate dan final crack.

Development of trimming technology for hot rolled ultra-low carbon steel

1993 ◽  
Vol 90 (7-8) ◽  
pp. 917-922
Author(s):  
Y. Matsuda ◽  
M. Nishino ◽  
J. Ikeda
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Ultra Low Carbon Steel ◽  
Hot Rolled
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