In-Situ Laser Ultrasound Measurements of Austenitic Grain Growth in Plain Carbon Steel

2021 ◽  
Author(s):  
Christian Kerschbaummayr ◽  
Martin Ryzy ◽  
Bernhard Reitinger ◽  
Mike Hettich ◽  
Jan Džugan ◽  
...  
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Grain Growth ◽  
Plain Carbon Steel ◽  
Ex Situ ◽  
Ultrasound Measurement ◽  
Laser Ultrasound ◽  
Austenite Grain Size ◽  
Ultrasound Measurements

Abstract The macroscopic mechanical properties like yield-strength, ductility or hardness play an important role during the steel production and the design of new steel grades. The austenite grain size is an important parameter, which influences the final microstructure and the properties of a material. When developing grain growth evolution models, typically many samples have to be treated thermally and micrographs have to be prepared ex-situ. To reduce the time expenditure of this procedure we carried out in-situ laser ultrasound measurements of austenitic grain growth in plain carbon steel (AISI 1045). A thermomechanical simulator of the type Linseis L78/RITA has been upgraded with a laser ultrasound measurement system, which enables the continuous and contactless determination of the austenite mean grain size during a thermal cycle. In this work we will show the calibration workflow and grain size results by a new attenuation model for plain carbon steel. In-situ laser ultrasound measurement data is compared with several micrographs defined at supporting points along a specified temperature program to corroborate the findings.

Plain Carbon Strip Q235 Grain Growth in Reheating Progress

2012 ◽  
Vol 528 ◽  
pp. 172-175
Author(s):  
Chun Li Mo ◽  
Shou Peng Du ◽  
Xu Ming Guo ◽  
Lie Shan Cui
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Grain Growth ◽  
Hot Rolling ◽  
Physical Simulation ◽  
Rolling Process ◽  
Plain Carbon Steel ◽  
Kinetics Equation ◽  
Reheat Furnace ◽  
Hot Rolling Process

Before hot rolling the ingot of plain carbon steel Q235 should be heated to austenite temperature to decrease distortion resistance. The grain size will affect the following hot rolling process. In this paper, the behaviour of Q235 grain growth in reheat furnace was studied with the method of physical simulation. To achieve the equation of grain growth in heating progress, the samples was carried out in different peak temperature and holding time at the Gleeble1500. With the kinetics equation grain size can be calculated and the results provide a basis for the setting of progress parameter during reheating of ingot.

scholarly journals Anisotropic Pinning-Effect of Inclusions in Mg-Based Low-Carbon Steel

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2241
Author(s):  
Chi-Kang Lin ◽  
Hsuan-Hao Lai ◽  
Yen-Hao Su ◽  
Guan-Ru Lin ◽  
Weng-Sing Hwang ◽  
...  
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Grain Boundary ◽  
Low Carbon Steel ◽  
In Situ Observation ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Austenite Grain Boundary

In this study, the effect of austenite grain size on acicular ferrite (AF) nucleation in low-carbon steel containing 13 ppm Mg is determined. The average austenite grain size was calculated using OM Leica software. Results show that the predicted and experimental values of austenite grain size are extremely close, with a deviation of less than 20 µm. AF formation is difficult to induce by either excessively small and large austenite grain sizes; that is, an optimal austenite grain size is required to promote AF nucleation probability. The austenite grain size of 164 µm revealed the highest capacity to induce AF formation. The effects of the maximum distance of carbon diffusion and austenite grain size on the microstructure of Mg-containing low carbon steel are also discussed. Next, the pinning ability of different inclusion types in low-carbon steel containing 22 Mg is determined. The in situ observation shows that not every inclusion could inhibit austenite grain migration; the inclusion type influences pinning ability. The grain mobility of each inclusion was calculated using in situ micrographs of confocal scanning laser microscopy (CSLM) for micro-analysis. Results show that the austenite grain boundary can strongly be pinned by Mg-based inclusions. MnS inclusions are the least effective in pinning austenite grain boundary migration.

Evaluation of Austenite Grains Growth in High Nb and Low Nb HSLA Steel

2020 ◽  
Vol 1000 ◽  
pp. 404-411
Author(s):  
Eddy S. Siradj
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Oil And Gas ◽  
Hsla Steel ◽  
Large Diameter ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Reheating Process ◽  
Austenite Grain Growth

This study was presented due to the increasing demand of High Strength Low Alloy (HSLA) steel, such as demand for thinner-walled and large diameter pipes in oil and gas industries. In order to meet the imposed economic restrictions, the high standard of all kinds of steel properties is required and can be achieved by controlling the steel microstructure. The austenite grain size influences the microstructure and properties of steel significantly, in which fine austenite grain size leads to higher strength, better ductility, and higher toughness. Studying the behavior of steel grain growth during the reheating process is still being a fascinating subject. P.R. Rios and D Zollner [1] mentioned that grain growth is the most important unresolved issue that has been a topic of research for many years. In this research, the behavior of austenite grain growth at a high niobium-low carbon (High Nb-low C) and low Nb-high C HSLA steel was evaluated, and the result was compared with other investigation. The results found that the austenite grain growth at high Nb-high C steel was slower than the growth at a low Nb-low C steel. The activation energy of austenite grain growth and both constant A and exponent n ware determined close agreement was obtained between the prediction of the model and the experimental grain size value.

Effect of Different Cooling Paths on the Microstructure and Properties of a Plain Carbon Steel

2013 ◽  
Vol 762 ◽  
pp. 171-175
Author(s):  
Jin Guo ◽  
Shui Ping Hu ◽  
Zhen Li Mi ◽  
Dong Bin Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Carbon Steel ◽  
Hot Rolling ◽  
Plain Carbon Steel ◽  
Controlled Cooling ◽  
Microstructure And Properties ◽  
Ultra Fast Cooling ◽  
Cooling Method ◽  
Fast Cooling

The effect of different cooling paths on the microstructure and properties of a plain carbon steel was carefully investigated by thermal simulation, hot rolling, tensile tests and quantitative metallography. Experimental results indicate that the more rapid the cooling rate is, the smaller the average ferritic grain size is and the higher the mechanical properties are. Both ultra fast cooling method and ultra fast cooling+accelerated controlled cooling method could refine grain size and improve mechanical properties. Without any alloy addition, using the ultra fast cooling immediately after hot rolling process, the yield strength of the plain carbon steel could reach 360 MPa and the elongation is 32%.

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