Influence of Copper on Redistribution Behaviour of Boron in Titanium Stabilized and Low Carbon Steel as Observed by Neutron Induced Alpha Autoradiography

2013 ◽  
Vol 794 ◽  
pp. 502-506 ◽  
Author(s):  
Bharat B. Shriwastwa ◽  
Arun Kumar
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Grain Boundaries ◽  
Creep Strength ◽  
Nuclear Reactor ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
Carbon Corrosion ◽  
Void Swelling

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.

scholarly journals Effect of Thermomechanical Treatment on Acicular Ferrite Formation in Ti–Ca Deoxidized Low Carbon Steel

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 296 ◽  
Author(s):  
Chao Wang ◽  
Xin Wang ◽  
Jian Kang ◽  
Guo Yuan ◽  
Guodong Wang
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Grain Boundaries ◽  
Cooling Rate ◽  
Thermomechanical Treatment ◽  
Acicular Ferrite ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Transformation Mechanism ◽  
Ferrite Formation

Transformation behaviors and mechanical properties under thermomechanical treatment conditions of Ti–Ca deoxidized low carbon steel were studied in comparison to Al–Ca treated steel. A thermomechanical simulation and a hot rolling experiment were carried out. Inclusions and microstructures were characterized, and the transformation mechanism was analyzed. The results indicated that typical inclusions in Ti–Ca deoxidized steel were TiOx-MnS-Al2O3-CaO, TiOx-MnO-Al2O3-CaO, and TiOx-MnS, which were effective for acicular ferrite (AF) nucleation. Acicular ferrite formation temperature decreased with an increase in cooling rate. A fine AF dominant microstructure was formed under a high driving force for the transformation from austenite to ferrite at lower temperatures. A high deformation of 43–65% discouraged the formation of acicular ferrite because of the increase in austenite grain boundaries serving as nucleation sites. The fraction of high-angled grain boundaries that acted as obstacles to cleavage cracks was the highest in the sample cooled at 5 °C/s because of full AF structure formation. The hardness increased significantly as the cooling rate increased from 2 to 15 °C/s, whereas it decreased under the condition of deformation because of the formation of (quasi-)polygonal ferrite. By applying accelerated water cooling, the mechanical properties, particularly impact toughness, were significantly improved as a result of fine AF microstructure formation.

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
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Carbon Steel ◽  
High Resistance ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
Mechanical Parts ◽  
Carbonization Process ◽  
Different Temperatures

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.

Microstructure and Mechanical Properties of Cooled and Tempered Cu and Nb-Bearing Ultra-Low Carbon Steels

2010 ◽  
Vol 638-642 ◽  
pp. 3242-3247 ◽  
Author(s):  
Hui Guo ◽  
Zhi Qiang Yao ◽  
Shan Wu Yang ◽  
Xin Lai He
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Steel Plates ◽  
Low Carbon ◽  
Niobium Content ◽  
Low Carbon Steels ◽  
Microstructure And Mechanical Properties ◽  
Ultra Low Carbon Steel

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.

Influence of laser surface hardened layer on mechanical properties of re-engineered low carbon steel sheet

2017 ◽  
Vol 685 ◽  
pp. 168-177 ◽  
Author(s):  
Badirujjaman Syed ◽  
Sulthan Mohiddin Shariff ◽  
Gadhe Padmanabham ◽  
Shaumik Lenka ◽  
Basudev Bhattacharya ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Steel Sheet ◽  
Low Carbon Steel ◽  
Hardened Layer ◽  
Laser Surface ◽  
Low Carbon ◽  
Carbon Steel Sheet ◽  
Surface Hardened Layer

Microstructure and Mechanical Properties of a Low-Carbon Steel Treated by One-Step Quenching and Partitioning Process

2014 ◽  
Vol 1082 ◽  
pp. 202-207 ◽  
Author(s):  
Shu Yan ◽  
Xiang Hua Liu
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Microstructural Evolution ◽  
Retained Austenite ◽  
Uniform Elongation ◽  
Low Carbon Steel ◽  
Total Elongation ◽  
Low Carbon ◽  
Quenching And Partitioning ◽  
Partitioning Time

A low carbon steel was treated by quenching and partitioning (Q&P) process, and a detailed characterization of the microstructural evolution and testing of mechanical properties were carried out. The resulted mechanical properties indicate that with the partitioning time increasing, the tensile strength decreases rapidly first and then remains stable, and the total elongation increases first then decreases. The investigated steel subjected to Q&P process exhibits excellent products of strength and elongation (17.8-20.6 GPa•%). The microstructural evolution of martensite matrix during the partitioning step was observed, and the morphology and content of retained austenite were characterized. The working hardening behavior of the samples was analyzed, and the retained austenite with higher carbon content contributes to the uniform elongation more effectively.

Microstructures and mechanical properties of equal-channel angular pressed low carbon steel

2000 ◽  
Vol 42 (7) ◽  
pp. 695-699 ◽  
Author(s):  
Dong Hyuk Shin ◽  
Chang Woo Seo ◽  
Jongryoul Kim ◽  
Kyung-Tae Park ◽  
Wung Young Choo
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Microstructures And Mechanical Properties
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