Mechanical Properties and Anisotropies of 0.2% Carbon Steel with Bimodal Microstructure Subjected to Heavy-Reduction Controlled-Rolling Process

2015 ◽  
Vol 87 (7) ◽  
pp. 947-956 ◽  
Author(s):  
Hyung-Won Park ◽  
Kei Shimojima ◽  
Sumio Sugiyama ◽  
Hisanao Komine ◽  
Jun Yanagimoto
2019 ◽  
Vol 8 (1) ◽  
pp. 1353-1365 ◽  
Author(s):  
Mohammad Masoumi ◽  
Edwan Anderson Ariza Echeverri ◽  
Cleiton Carvalho Silva ◽  
Willys Machado Aguiar ◽  
Hamilton Ferreira Gomes de Abreu

Author(s):  
V.G. Razdobreev ◽  
D.G. Palamar

The aim of the work is to study the influence of the process of hot asymmetric rolling on the structural state, mechanical properties and operational characteristics of long products of simple form from ordinary carbon steel. To simulate the process of asymmetric high-quality rolling, the mathematical model previously developed in the ISI added the possibility of taking into account cases of rolling in a pair of rolls of different diameters, rolling in a pair of rolls of different materials, rolling with one drive and one non-drive rolls, rolling at different speeds in a pair of rolls and other. The calculations showed a reduction in rolling force to 10 % with an asymmetric rolling process compared to the traditional rolling process. The study of the features of the process of hot asymmetric rolling (shear rolling) compared with the traditional rolling process was carried out under industrial conditions in the production of a 12x12 mm square profile from ordinary low-carbon steel St3sp. It was found that the average values of HRB, σВ, and σТ in the studied samples practically do not differ, and the average values of δ5 are higher by 8 % (abs.) or ~ 27 % (rel.) In samples that were rolled using the asymmetric rolling technology than in samples that were rolled using traditional rolling technology. The estimation of dislocation density by the X-ray diffraction method showed that during hot asymmetric rolling, the dislocation density is reduced by ~ 46% due to the active flow of in-situ polygonization and recrystallization processes during deformation. In this case, the average values of the microfractures of the crystalline lattice of ferrite are 21% lower in the samples obtained by the method of asymmetric rolling than in the samples obtained by traditional rolling. For the first time, a decrease in the total atmospheric corrosion rate was found in samples that were rolled using asymmetric rolling technology (0.39 g/m2xh) compared to samples that were rolled using traditional rolling technology (0.445 g/m2xh).


Author(s):  
H. Meuser ◽  
F. Grimpe ◽  
S. Meimeth ◽  
A. Liessem

The Thermomechanically Controlled Rolling Process (TMCP) is used to produce heavy plates for a wide field of applications due to the excellent combination of mechanical properties, strength and toughness properties as well as excellent weldability. In order to achieve these properties lean alloying concepts with microalloying of Nb, Ti and/or V in combination with temperature controlled rolling are used. The basic metallurgical properties are controlled recrystallisation, α/γ grain refinement, phase transformation and precipitation hardening. This paper deals with the evaluation of an alternative alloying concept for a major plate order for the construction of an export subsea gas pipeline in grade X70. The challenge of this project was focussed on the evaluation of an alloying concept which was able to meet the demands of an offshore grade X70 and in addition to fulfil severe requirements regarding weldability and toughness properties. In addition to the aforementioned requirements the alloying concept had of course to be within the restrictions of the customer specification. Before start of production a suitable process design had to be developed in a laboratory scale as well as large scale trials. Special focus was laid on the influence of rolling parameters on the obtained mechanical properties. Therefore different alloying concepts and the achieved mechanical properties as well as temperature ranges for the rolling process will be reviewed and presented. The finally chosen product and process design lead to excellent results which stayed in a very narrow scatter band throughout the mass production of more than 300,000 tons.


2014 ◽  
Vol 852 ◽  
pp. 178-182
Author(s):  
Shuo Li ◽  
Di Tang ◽  
Hui Bin Wu ◽  
Ji Guang Xiong

The 304 austenite stainless steel and low carbon steel clad plate was fabricated by casting and hot rolling process. The mechanical properties and interface shear strength of clad plates with different thickness after rolling were investigated in detail. The microstructure characteristics of the clad interface were observed by SEM (Scanning Electron Microscope). The phases and chemical composition were analyzed by XRD (X-ray diffraction) and EDS (energy dispersive spectroscopy). Based on the results, the mechanical properties and interface shear strengths meet the requirements of national standards. No visible cracks were observed in the clad interface after bending test. Cr3C2precipitates, Fe3O4oxides and Fe-Cr intermetallic compound were distributed around the interface of clad plate after casting, but a good metallurgical bonding was achieved after hot-rolling.


2011 ◽  
Vol 682 ◽  
pp. 97-101
Author(s):  
Zhan Ling Zhang ◽  
Ke Ke Zhang ◽  
Yun Yue ◽  
Ning Ma ◽  
Zhi Wei Xu

An ultrahigh carbon steel alloy containing 1.4 wt pct carbon (UHCS-1.4C) was studied. The steel was processed into ultrafine grain and fully spheroidized microstructure through a controlled rolling and controlled-cooling divorced eutectoid transformation, and was then given austempering treatment to form bainite. The mechanical properties of the heat-treated steel were evaluated by tension tests at room temperature. After austenitized at 850 °C and then austempered at 300 - 350 °C, the microstructure was ultrafine upper bainite, retained austenite, and unsolvable cementite. It was shown that the ultimate tensile strengths of UHCS-1.4C ranged from 1420 to 1830 MPa, elongations to failure from 6 to 14%; the ultimate tensile strength increases with decreasing austempering temperature, while the tensile ductility decreases. The fracture surface of bainitic UHCS-1.4C consists mainly of dimples and voids, which reveal a ductile fracture. The present results indicate that ultrahigh carbon steel can be easily processed to achieve bainitic microstructures and unique properties.


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.


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