Improvement of the Adhesive Wear Resistance and Mechanical Properties of Low-Carbon Steel by Solid Carbonization

2013 ◽  
Vol 553 ◽  
pp. 81-86
Author(s):  
M. Noor. I. Dabo ◽  
M.S. Aldlemey

Wear is one of the problems that occurs in moving parts, whether rolling or sliding. Since the wear resistance is closely linked to the hardness of the involved surfaces, this research studies the possibility of increasing the hardness of low carbon steel, which is used extensively because its ductility and its shock resistance and being one of the inexpensive metals. A lot of mechanical parts require an external hard surface, resistant to wear, and at the same time high resistance to shocks. The main hardening process used in this research is the increase of the carbon proportion on the external surfaces of the equipment made of low carbon steel and thus, to make the heat treatments necessary to obtain the required properties of these surfaces such as hardness and high resistance to shocks. The study of the process of carbonization by using the solid carbonization as one of the ways of hardening the surface at temperatures in the austenite range of low carbon steels give an impression about the possibility of improvement in the qualities of hardness and resistance to wear. In order to obtain a variable thickness of the carbonated layer, a carbonization process was performed at different temperatures and times to demonstrate the effect of these two important factors to the amount of diffused carbon to the surface of the solid and thus the extent of its influence to obtain the required properties of the process. The mechanical and microscopic tests conducted on samples proved the success of the carbonization process to achieve the purpose and goal of the preparation of this paper. Finally experimental results have shown good correlation between the wear resistance and mechanical properties with temperature and carbonization time. The analysis of the variance of the results in this study indicated that the best mechanical properties are achieved when one performs the process of carbonization at 975°C for 20 hours.

2013 ◽  
Vol 794 ◽  
pp. 502-506 ◽  
Author(s):  
Bharat B. Shriwastwa ◽  
Arun Kumar

Boron content and its distribution play a significant role in modifying the metallurgical and mechanical properties of many steels and alloy at lower level of concentration. Precipitation of boron at the grain boundaries, have shown to improve the creep strength in titanium stabilized steel, high temperature ductility in low carbon corrosion resistant steel and the hardenability in low carbon steel in general. Titanium-stabilized steel (DIN 1.4970), was developed as a possible material for fast breeder sodium-cooled nuclear reactor core components for its superior creep strength, high micro-structural stability and elevated void swelling resistance. It is well known that, helium produced during neutron irradiation through the 10B(n,α)Li7 reaction, affects the mechanical properties and the amount of void swelling in nuclear reactor materials. Two nos. of Ti-stabilized steel samples with 40ppm boron and 2ppm boron (DIN 1.4970 & DIN1.4970LB steel) were analyzed for boron re-distribution behavior during different thermo-mechanical treatment using a technique known as Neutron Induced Alpha Autoradiography (NIAA). This technique is a well known technique, and widely used for revealing the spatial distribution of boron in the materials with a resolution approaching to ppm level. This technique has also been used to detect the influence of copper addition on boron distribution pattern in steel specimen. Mapping of boron autoradiography of Low carbon steels containing 20ppm of boron with and without copper was able to demonstrate this behavior. Boron track mapping of Low carbon steel without copper, in solution annealing treatment, show the uniform distribution of boron throughout the matrix, whereas when the similar steel with 1.48% copper was mapped, it shows the precipitation of boron at the grain boundaries.


2010 ◽  
Vol 638-642 ◽  
pp. 3242-3247 ◽  
Author(s):  
Hui Guo ◽  
Zhi Qiang Yao ◽  
Shan Wu Yang ◽  
Xin Lai He

To improve the toughness and weldability, the carbon content of the steels has to be deduced, and more and more attention has been attracted to the low carbon and ultra-low carbon steels. To strengthen the microstructure Cu and Nb-bearing steels are developed. However, the knowledge on influence of combined addition of Cu and Nb is still in lack. The microstructure and mechanical properties are studied in the 6-mm thick as-rolled and tempered ultra-low carbon steel plates with varied copper and niobium content. The microstructure and mechanical properties are studied in the 6-mm thick as-rolled and tempered ultra-low carbon steel plates with varied copper and niobium content. The experimental results show that if niobium is added without copper, the increase of niobium addition does not have a significant influence on the phase transformation and mechanical properties before tempering. The strength and toughness of those copper-free niobium steels do not vary significantly after tempered at different temperatures, while the strength of niobium steels with 1.8% copper added increases after tempered in the range of 450-650°C and reaches a peak at 500-550°C. If combined with 1.8% copper, the increase of niobium addition from 0.08% to 0.16% improves the hardenabililty and strength significantly, and the strength peak after tempering moves to a lower temperature. The strength of air-cooled niobium steels with 1.8% copper added is usually higher than those water-cooled, while after tempered at a proper temperature, the strength of the latter becomes higher than the former.


2019 ◽  
Vol 813 ◽  
pp. 159-164
Author(s):  
Carlos Alberto Souto ◽  
Gustavo Faria Melo da Silva ◽  
Laura Angelica Ardila Rodriguez ◽  
Aline C. de Oliveira ◽  
Kátia Regina Cardoso

Coatings with high entropy alloys of the AlCoCrFeNiV system were obtained by selective laser melting on low carbon steel substrates. The effect of the variation of the Fe and V contents as well as the laser processing parameters in the development of the coating were evaluated. The coatings were obtained from the simple powder mixtures of the high purity elemental components in a planetary ball mill. The coatings were obtained by using CO2 laser with a power of 100 W, diameter of 0.16 mm, and scan speed varying from 3 to 12 mm/s. Phase constituents, microstructure and hardness were investigated by XRD, SEM, and microhardness tester, respectively. Wear resistance measurements were carried out by the micro-abrasion method using ball-cratering tests. The coatings presented good adhesion to the substrate and high hardness, of the order of 480 to 650 HV. Most homogeneous coating with nominal composition was obtained by using the higher scan speed, 12 mm/s. Vanadium addition increased hardness and gave rise to a high entropy alloy coating composed by BCC solid solutions. Ball cratering tests conducted on HEA layer showing improvement of material wear resistance, when compared to base substrate, decreasing up to 88% its wear rate, from 1.91x10-6 mm3/Nmm to 0.23x10-6 mm3/Nmm.


2017 ◽  
Vol 685 ◽  
pp. 168-177 ◽  
Author(s):  
Badirujjaman Syed ◽  
Sulthan Mohiddin Shariff ◽  
Gadhe Padmanabham ◽  
Shaumik Lenka ◽  
Basudev Bhattacharya ◽  
...  

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