Heat Treatment Conditions of Low Carbon Steel Part Used in the Deep Sea

Author(s):  
Sang-Seop Lim ◽  
Chung-Gil Kang

With increasing oil consumption, we have to find more oil resources in the deep sea. The extreme working condition of the deep sea requires high toughness and high strength values at low temperatures. Academic institutions limited the chemical composition of the requested casting steel to meet their requirements of fracture toughness and weldability. Thus, the carbon content was set approximately 0.10% based on classification societies which required specific mechanical properties of strength, elongation, reduction area and impact energy (−40°C). In this study, we find the optimal heat treatment condition of low carbon steel (0.10%C) to obtain the desired mechanical properties at low temperature (−40°C) according to different quenching parameters (heating times) and tempering parameters (heating temperatures, cooling methods).

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Le Van Long ◽  
Dinh Van Hien ◽  
Nguyen Truong Thanh ◽  
Nguyen Chi Tho ◽  
Van Thom Do

The low carbon steel has good ductility that is favorable for forming process, but its low strength leads to limiting their application for forced structures. This paper studied improving strength of low-carbon steel via rolling deformation and dual-phase treatment. The results showed that the dual-phase treated steel had a combination of high strength and good ductility; its tensile ultimate strength reached 740 MPa with elongation at fracture of over 15%, while that of the cold-rolled steel only reached 700 MPa with elongation at fracture of under 3%. Based on the obtained results, relationships between mechanical properties and dual-phase processing parameters were established to help users choose suitable-processing parameters according to requirements of products.


2016 ◽  
Vol 47 (10) ◽  
pp. 5049-5057 ◽  
Author(s):  
Jian Zhang ◽  
Pei-Hsien Feng ◽  
Yan-Chi Pan ◽  
Weng-Sing Hwang ◽  
Yen-Hao Su ◽  
...  

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 16 (1) ◽  
pp. 14-18
Author(s):  
Liviu Dorin Pop

Abstract The way a piece or tool behaves in operation is determined by the quality of the material from which it is made, the precision of execution and heat treatment applied. In the present research, it is highlighted the differences that take shape after heat treating different materials (low carbon steel and high alloyed steel) including heating to dissimilar austenitic phases (880°C and 1020°C), holding for non-identical times, tempering at low temperature (260 °C) and then cooling by using separate cooling mediums (oil, air and water). The results show no noticeable increase in the hardness and mechanical properties for the low carbon steel after the heat treatment, but on the other hand, the high alloyed steel, reveals distinguishable changes in both hardness and mechanical properties. There is a close link between the structure, the parameters of the thermal processes and the properties that are desired so that future specialists have to assimilate the basic knowledge related to the phenomena that occur during a heat treatment but at the same time it is important to equip the companies with machines and measure devices, like a spectrometer.


Metallurgist ◽  
2018 ◽  
Vol 61 (9-10) ◽  
pp. 777-781
Author(s):  
V. V. Tsukanov ◽  
V. G Milyuts ◽  
O. E. Nigmatulin ◽  
S. A. Golosienko ◽  
S. V. Efimov ◽  
...  

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