scholarly journals Effect of Microstructure on Post-Rolling Induction Treatment in a Low C Ti-Mo Microalloyed Steel

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 694 ◽  
Author(s):  
Gorka Larzabal ◽  
Nerea Isasti ◽  
Jose Rodriguez-Ibabe ◽  
Pello Uranga
Keyword(s):  
Hot Rolling ◽  
Microalloyed Steel ◽  
Rapid Heating ◽  
Laboratory Simulation ◽  
Thin Strip ◽  
Induction Treatment ◽  
Heating Process ◽  
Low Carbon ◽  
Optimization Strategy ◽  
Hot Rolled

Cost-effective advanced design concepts are becoming more common in the production of thick plates in order to meet demanding market requirements. Accordingly, precipitation strengthening mechanisms are extensively employed in thin strip products, because they enhance the final properties by using a coiling optimization strategy. Nevertheless, and specifically for thick plate production, the formation of effective precipitation during continuous cooling after hot rolling is more challenging. With the aim of gaining further knowledge about this strengthening mechanism, plate hot rolling conditions were reproduced in low carbon Ti-Mo microalloyed steel through laboratory simulation tests to generate different hot-rolled microstructures. Subsequently, a rapid heating process was applied in order to simulate induction heat treatment conditions. The results indicated that the nature of the matrix microstructure (i.e., ferrite, bainite) affects the achieved precipitation hardening, while the balance between strength and toughness depends on the hot-rolled microstructure.

scholarly journals Effect of rapid heating process in hot stamping on compact strip production hot rolled plate

2018 ◽  
Vol 15 ◽  
pp. 1055-1061
Author(s):  
Bin Zhu ◽  
Jia Zhu ◽  
Zhoujie Zhu ◽  
Yilin Wang ◽  
Yisheng Zhang
Keyword(s):  
Rapid Heating ◽  
Hot Stamping ◽  
Rolled Plate ◽  
Heating Process ◽  
Compact Strip Production ◽  
Hot Rolled ◽  
Strip Production

Refinement of Cementite in High Strength Steel Plates by Rapid Heating and Tempering

2007 ◽  
Vol 539-543 ◽  
pp. 4720-4725 ◽  
Author(s):  
A. Nagao ◽  
K. Hayashi ◽  
K. Oi ◽  
S. Mitao ◽  
N. Shikanai
Keyword(s):  
Rapid Heating ◽  
High Strength ◽  
Average Diameter ◽  
Carbon Steels ◽  
Steel Plates ◽  
Heating Process ◽  
Low Carbon ◽  
Precipitation Behavior ◽  
Heating Rates ◽  
Extraction Replica

The precipitation behavior of cementite in low carbon steels at various heating rates from 0.3 to 100 K/s has been studied using a high-frequency induction heating apparatus. The materials used in this study were steel platesfor welded structures: 610 and 780 MPa class steel plates with a mixed microstructure of bainite and martensite.Cementite was observed using a carbon extraction replica method and the hardness and toughness were also examined. When heated at the conventional slow rate of 0.3 K/s, relatively large cementite particles with an average diameter of 72 nm precipitated at the lath boundaries, whereas when heated at a rapid rate over 3.0 K/s, cementite precipitated both within the laths and at the lath boundaries, and the cementite was refined down to an average diameter of 54 nm. With such refinement of the cementite, the toughness was improved. On the other hand, the hardness was irrespective of the heating rate and was dependent on the tempering parameter. TEM observations of the cementite precipitation behavior during the rapid heating process revealed that cementite begins to precipitate at the lath boundaries at about 773 K and within the laths at about 873 K. It is concluded that rapid heating especially from 773 to 873 K contributes to the cementite refinement and consequently the improvement in toughness. The effect of alloying elements such as chromium, molybdenum or silicon on the cementite growth during the rapid heating and tempering treatment is also discussed.

Influence of Initial Microstructure on Mechanical Properties of Cu Bearing Extra Low Carbon Steel Sheets

2010 ◽  
Vol 654-656 ◽  
pp. 306-309
Author(s):  
Sim Kun Min ◽  
Sung Il Kim ◽  
Jong Sang Kim ◽  
Moon Hi Hong
Keyword(s):  
Mechanical Properties ◽  
Hot Rolling ◽  
Low Carbon Steel ◽  
Onset Time ◽  
Continuous Annealing ◽  
Low Carbon ◽  
Initial Microstructure ◽  
Steel Sheets ◽  
Axial Tensile ◽  
Hot Rolled

This paper examines the effect of initial microstructure after hot rolling on the final microstructure and mechanical properties for Cu bearing Extra Low Carbon(ELC) Steel Sheets. For this purpose, two ELC steels having different initial microstructures due to different onset time of cooling after pilot hot rolling (0.4 and 1.2 second) were selected. Mechanical properties and microstructures were analyzed as well using uni-axial tensile test, electron back-scattered diffraction (EBSD) technique following pilot rolling and continuous annealing. It has been found that the reduction of onset time of cooling gives rise to the grain refinement in hot rolled sheets. The average grain sizes of hot rolled sheetss at the onset time of 0.4 and 1.2 second are 16.7μm and 20.8 μm, respectively. In addition, the planar anisotropy of the Cu bearing ELC steel sheets has improved with reducing onset time of cooling after hot rolling. However, other mechanical properties such as strength and elongation of annealed steel are similar to both cooling condition.

Development of Hot Rolled Strips for Internal Plates of Automobile

2015 ◽  
Vol 817 ◽  
pp. 415-420
Author(s):  
Xing Dong Peng ◽  
Mei Ling Wang ◽  
Sheng Li Li ◽  
Jie Xu
Keyword(s):  
Hot Rolling ◽  
Aluminum Content ◽  
Manganese Content ◽  
Fatigue Properties ◽  
Steel Melting ◽  
Low Carbon ◽  
Slab Continuous Casting ◽  
Rolling Line ◽  
Cold Rolled ◽  
Hot Rolled

The hot rolled strips for internal plates of automobile was developed by taking the technologies of low-carbon softening steel, including strictly control the chemical composition content during the steel melting and optimization of the rolling processes in the thin slab continuous casting and rolling line. The results showed that when carbon content was 0.04%, adding aluminum content or reducing silicon content and manganese content, reducing the reduction in previous rolling passes and increasing the reduction of the finishing pass at high temperature was beneficial for reducing the yield strength and tensile strength of the hot rolled strips. The precipitate of the samples after annealing showed that the precipitate of aluminum-nitride increased significantly at 850°C. And the texture of the samples after annealing showed that the main texture was {110} <001> and its intensity was 1.7-2.0, annealing with hot rolled strips did not benefit the advantageous texture. Tension-tension fatigue properties of hot rolled strips and cold rolled ones were determined, the results showed that the fatigue properties of hot rolling strips were rather higher than that of cold rolled ones. In the stamping experiments of some automobile parts, there was not any drawback, and the forming properties of hot rolling strips were equal to that of cold rolled ones. It was feasible to replace the cold rolled strips with the hot rolled ones for the internal plates of automobile.

scholarly journals Effect of Carbon Content on Microstructure, Properties and Texture of Ultra-Thin Hot Rolled Strip Produced by Endless Roll Technology

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6174
Author(s):  
Peng Tian ◽  
Guoming Zhu ◽  
Yonglin Kang
Keyword(s):  
Carbon Steel ◽  
Carbon Content ◽  
Electron Backscatter Diffraction ◽  
Low Carbon Steel ◽  
Microstructural Characterization ◽  
Thin Strip ◽  
Rolled Strip ◽  
Low Carbon ◽  
Hot Rolled Strip ◽  
Hot Rolled

In order to make a comprehensive comparison between ultra-thin hot rolled low carbon steel (LC) and extra low carbon steel (ELC) produced by endless roll technology and explain the differences, a detailed investigation into the microstructural characterization, characteristics of cementite and precipitates, mechanical properties, internal friction peaks, texture characterization by an X-ray powder diffractometer and electron backscatter diffraction, and formability including earing behavior, hole expanding ratio and V-shaped bending properties was carried out with different carbon content for 1.0 mm thickness ultra-thin hot rolled strip produced in endless strip production line. The experimental results indicate that the microstructure of both is composed of multi-layer areas with different grain sizes and thicknesses, the strength and elongation of LC are higher than that of ELC, but the content of solid solution carbon atoms and r of ELC are higher than that of LC, at the same time, the formability of ultra-thin strip ELC is better than that of LC mainly related to the content of {hkl} <110> and {111} <112> of ELC was higher than those of LC. The mechanical and formability properties of ultra-thin hot rolled strip by endless roll technology can meet the requirements of replacement cold rolled strip by hot rolled strip.

Effect of Controlled Cooling after Hot Rolling on the Mechanical Properties of a Low Carbon Niobium Microalloyed Steel Wire Rod

2018 ◽  
Vol 930 ◽  
pp. 333-338
Author(s):  
Felipe Farage David ◽  
Sayd Farage David ◽  
Renan Carreiro Rocha ◽  
Ricardo Arthur Sanguinetti Ferreira
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Thermomechanical Treatment ◽  
Hot Rolling ◽  
Microalloyed Steel ◽  
Steel Wire ◽  
Raw Material ◽  
Low Carbon ◽  
Coiling Temperature ◽  
Wire Rod

The wire rod has high relevance due to its wide application as a raw material for steel wire and wire processed in cold rolling mills and drawing. The control of process variables, such as cooling rate, coiling temperature, rolling speed is essential for obtaining the microstructures and therefore mechanical properties of the material. The purpose of this work is to study the behavior of the microstructure and mechanical properties with the variation of thermomechanical treatment in the hot rolling of wire rod. The steels used in this study were the microalloyed niobium steel equivalent to ASTM A913 grade 50 and carbon steel equivalent to ASTM A510 grade 1013. Despite the carbon steel has higher equivalent carbon to microalloyed steel, was found higher yield strength (σe) in the microalloyed niobium steel. Thus, by applying appropriate thermomechanical treatment in microalloyed steel is possible to improve mechanical properties mainly due to grain refining.

Nano-Scaled Fe3C Precipitates and Precipitation Strengthening in Hot Rolled Low Carbon High Strength Titanium Microalloyed Steel

2010 ◽  
Vol 146-147 ◽  
pp. 838-843
Author(s):  
Jian Feng Wang ◽  
Guang Qiang Li ◽  
Ai Da Xiao ◽  
Fu Jie
Keyword(s):  
Yield Strength ◽  
Microalloyed Steel ◽  
High Strength ◽  
Granular Bainite ◽  
Precipitation Strengthening ◽  
Strengthening Effect ◽  
Low Carbon ◽  
High Resolution Tem ◽  
Bainite Microstructure ◽  
Hot Rolled

Hot rolled Ti microalloyed steel with polygonal ferrite and granular bainite microstructure and 640 MPa yield strength has been developed in BOF-CSP process. By chemical phase analysis, XRD, EDS and high resolution TEM, the particle size distribution, morphology, composition, crystal structure of precipitates were identified. Results revealed the steel containing Ti exhibits fine and uniformly distributed Fe3C-type carbides, the amount of M3C particles less than 18 nm in size was 0.2565 mass %. The high strength of steel is attributed to the precipitation strengthening effect of Fe3C, the yield strength increment from precipitation strengthening of Fe3C calculated according to the formula by Olson and Ashby-Orowan attained 234.4 MPa.

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