scholarly journals Evaluation of combined heat treatment techniques of testing hardness and tensile strength of mild carbon steel commonly used in Nigeria

2019 ◽  
Vol 23 (3) ◽  
pp. 557
Author(s):  
Y Adamu ◽  
A.A. Adamu ◽  
Z Salihu ◽  
A.B. Musa
2021 ◽  
Vol 2133 (1) ◽  
pp. 012046
Author(s):  
Lei Chu

Abstract With the rapid development of materials, metal materials are used less and less, but at this stage, metal materials are still widely used, and iron and steel materials are the most widely used. Cracks often appear in the process of metal material processing and use, and these cracks will have a certain impact on the use of metal materials. The existence of microcracks will affect the mechanical properties of materials to some extent, but in most cases, the mechanical properties of materials will be greatly reduced, and in serious cases, metal materials will break directly in the process of use or processing. The crack healing process needed after the emergence of cracks can effectively change this situation, but so far, the research on metal crack healing is still not perfect. In this paper, taking the internal crack of low carbon steel as the object, the recovery of mechanical properties of low carbon steel by cyclic phase transformation heat treatment was studied. The results show that with the increase of the healing area, the microhardness of the area after crack healing also increases, and the tensile strength of the specimen also increases after the healing. When the healing area is similar, increasing the healing time and temperature will result in grain coarsening, resulting in the decrease of microhardness and tensile strength in the crack healing zone.


2019 ◽  
Vol 10 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Blaoui Mohammed Mossaab ◽  
Mokhtar Zemri ◽  
Mustapha Arab

Purpose The purpose of this paper is to evaluate the effects of medium carbon steel microstructure on the tensile strength and fatigue crack growth (FCG) behavior. Design/methodology/approach To achieve this aim, four different heat treatment methods (normalizing, quenching, tempering at 300°C and tempering at 600°C) were considered. Microstructural evolution was investigated by scanning electron microscopy. FCG rate tests were conducted on the resultant microstructures with compact tension specimens at room temperature by a standard testing method. Findings The results show that the normalized microstructure had the largest number of cycles to failure, indicating a high fatigue resistance, followed by the as received, tempered at 600°C, tempered at 300°C and quenched microstructure. Originality/value The paper shows the influence of the microstructure on the fatigue-propagation behavior with the definition of the Paris parameters of each heat treatment condition.


2018 ◽  
Vol 4 (2) ◽  
pp. 294 ◽  
Author(s):  
Sumar Hadi Suryo ◽  
Susilo Adi Widyanto ◽  
Paryanto Paryanto ◽  
Aly Syariati Mansuri

Excavator is heavy equipment that usually used in construction and mining works. Bucket teeth which are located in the tip of bucket excavator are used for digging works. They are easily damaged by direct contact with the media. One of the material used in bucket teeth excavator is mild carbon steel that has carbon content between 0.33%-0.5%. However, the hardness value of this material is not yet meets the standard of bucket teeth excavator so the optimum hardness value based on its heat treatment should be known. Besides that, its tensile, impact strength, and micro structure in optimum condition will also know. Optimization method was done through Taguchi experimental design with L9 orthogonal and ANOVA (Analysis of Variance). Factors or parameters in this research were heating temperature, holding time, quenching media, and tempering temperature. In this experiment, nine specimens of mild carbon steel were tested by different heating temperatures (850oC, 875oC, 900oC), different holding times (60, 90, and 120 minutes), different quenching medias (oil, water, and salt water), and different tempering temperatures (250oC, 450oC, 650oC). Calculation of Taguchi method and confirmation experiment showed that the optimum parameters of hardness are 875oC heating temperature, 60 minutes holding time, water quenching media, and 250oC tempering temperature. Meanwhile, ANOVA test showed a result that the four factors had an effect on the bucket teeth excavator hardness.


Author(s):  
R. Suresh

The effect of various heat treatment operations (annealing, normalizing and hardening) on mechanical properties of medium carbon steel was investigated. The samples were prepared and heat-treated at 770 ºC subsequently was cooled by different quenching media. The mechanical properties of the treated and untreated samples were determined using standard methods. Results showed that the mechanical properties of carbon steel can be changed and improved by various heat treatments. It was also found that the annealed samples has the lowest tensile strength and hardness value and highest ductility, while hardened samples has the highest tensile strength and hardness value and lowest ductility value.


2018 ◽  
Vol 18 (1) ◽  
pp. 125-135
Author(s):  
Sattar H A Alfatlawi

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.


Alloy Digest ◽  
1978 ◽  
Vol 27 (9) ◽  

Abstract UNIFLUX 70 is a continuous flux-cored welding electrode (wire) for welding in carbon dioxide shielding gas in the flat groove and horizontal fillet positions. It is used widely in shipbuilding and other fabricating industries to weld carbon steel and provides around 82,000 psi tensile strength and around 50 foot-pounds Charpy V-notch impact at 0 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: CS-74. Producer or source: Unicore Inc., United Nuclear Corporation.


Alloy Digest ◽  
1990 ◽  
Vol 39 (12) ◽  

Abstract VASCOMAX T-300 is an 18% nickel maraging steel in which titanium is the primary strengthening agent. It develops a tensile strength of about 300,000 psi with simple heat treatment. The alloy is produced by Vacuum Induction Melting/Vacuum Arc Remelting. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-454. Producer or source: Teledyne Vasco.


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