Atomic scale effects of alloying, partitioning, solute drag and austempering on the mechanical properties of high-carbon bainitic–austenitic TRIP steels

Seol, Jae Bok; Raabe, Dierk; Choi, P. P.; Im, Yung-Rok; Park, Chan-Gyung

doi:10.1016/j.actamat.2012.07.064

Cited by 135 publications

(82 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…18(a)). The carbon depleted area having 0.6 at.% carbon was bainitic ferrite lath according to published researches [39,45]. The carbon content in this enriched area was approximately 25 at.% (Figs.…”

Section: Ebsd and Apt Analysis Of The T 400 Samplementioning

confidence: 99%

“…It was reported that the nano-scale carbides precipitation could take place despite a high silicon concentration (1.5 wt. %) in TRIP steel [39,49]. When the IBT temperature increased to 450 °C, the amount of RA decreased to 0.025±0.002.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

“…After holding at 670 °C for 90 s, samples were quickly cooled at a rate of 50 Ks -1 to IBT temperature in order to avoid pearlite formation during cooling [38,39] and then held for 900 s (in order to simulate the coiling process in industry). Four IBT temperatures of 350, 400, 450 and 500 °C were chosen.…”

Section: Microstructure Characterisationmentioning

confidence: 99%

See 2 more Smart Citations

Microstructures and mechanical properties of TRIP steel produced by strip casting simulated in the laboratory

Xiong

Kostryzhev

Saleh

et al. 2016

Materials Science and Engineering: A

View full text Add to dashboard Cite

Conventional transformation induced plasticity (TRIP) steel (0.17C-1.52Si-1.61Mn-0.03Al, wt%) was produced via strip casting technology simulated in the laboratory. Effects of holding temperature, holding time and cooling rate on ferrite formation were studied via analysis of the continuous cooling transformation diagram obtained here. A typical microstructure for conventional TRIP steels consisting of ~ 0.55 fraction of polygonal ferrite with bainite, retained austenite and martensite was obtained. However, coarse prior austenite grain size of ~80 μm led to large polygonal ferrite grain size of ~17 μm, coarse second phase regions of ~21 μm size, small amount of retained austenite (0.02-0.045) and the presence of Widmanstätten ferrite. Optimisation of the microstructure-property relationship was reached via a variation in the isothermal bainite transformation temperature. The highest retained austenite fraction of 0.045±0.003 with medium carbon content of 1.23±0.01 wt% was obtained after holding at 400 °C, resulting in the highest ultimate tensile strength of 590±35 MPa and largest total elongation of 0.27±0.05. The presence of TRIP effect in the studied steel was revealed through the analysis of strain hardening exponent and modified Crussard-Jaoul model. Effect of processing parameters on retained austenite retention and stress-strain behaviour was discussed. Conventional transformation induced plasticity (TRIP) steel (0.17C-1.52Si-1.61Mn-0.03Al, wt. %) was produced via strip casting technology simulated in the laboratory. Effects of holding temperature, holding time and cooling rate on ferrite formation were studied via analysis of the continuous cooling transformation diagram obtained here. A typical microstructure for conventional TRIP steels consisting of ~ 0.55 fraction of polygonal ferrite with bainite, retained austenite and martensite was obtained. However, coarse prior austenite grain size of ~ 80 μm led to large polygonal ferrite grain size of ~ 17 μm, coarse second phase regions of ~ 21 μm size, small amount of retained austenite (0.02 -0.045) and the presence of Widmanstätten ferrite. Optimisation of the microstructure-property relationship was reached via a variation in the isothermal bainite transformation temperature. The highest retained austenite fraction of 0.045±0.003 with medium carbon content of 1.23±0.01 wt. % was obtained after holding at 400 °C, resulting in the highest ultimate tensile strength of 590±35 MPa and largest total elongation of 0.27±0.05. The presence of TRIP effect in the studied steel was revealed through the analysis of strain hardening exponent and modified Crussard -Jaoul model. Effect of processing parameters on retained austenite retention and stress-strain behaviour was discussed.

show abstract

Section: Ebsd and Apt Analysis Of The T 400 Samplementioning

confidence: 99%

Section: Mechanical Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Microstructures and mechanical properties of TRIP steel produced by strip casting simulated in the laboratory

Xiong

Kostryzhev

Saleh

et al. 2016

Materials Science and Engineering: A

View full text Add to dashboard Cite

show abstract

“…APT was employed to study the elemental distributions in spheroidized carbides and bainite. [16] The partitioning behavior of carbon and other alloy elements across the phase boundaries are discussed, with an emphasis on the effect of Cr, Mn, and Si on the growth kinetics of cementite.…”

mentioning

confidence: 99%

On the Spheroidized Carbide Dissolution and Elemental Partitioning in High Carbon Bearing Steel 100Cr6

Song

Choi

Inden

et al. 2013

Metall Mater Trans A

Self Cite

View full text Add to dashboard Cite

We report on the characterization of high carbon bearing steel 100Cr6 using electron microscopy and atom probe tomography in combination with multi-component diffusion simulations. Scanning electron micrographs show that around 14 vol pct spheroidized carbides are formed during soft annealing and only 3 vol pct remain after dissolution into the austenitic matrix through austenitization at 1123 K (850°C) for 300 seconds. The spheroidized particles are identified as (Fe, Cr) 3 C by transmission electron microscopy. Atom probe analysis reveals the redistribution and partitioning of the elements involved, i.e., C, Si, Mn, Cr, Fe, in both, the spheroidized carbides and the bainitic matrix in the sample isothermally heat-treated at 773 K (500°C) after austenitization. Homogeneous distribution of C and a Cr gradient were detected within the spheroidized carbides. Due to its limited diffusivity in (Fe, Cr) 3 C, Cr exhibits a maximum concentration at the surface of spheroidized carbides (16 at. pct) and decreases gradually from the surface towards the core down to about 2 at. pct. The atom probe results also indicate that the partially dissolved spheroidized carbides during austenitization may serve as nucleation sites for intermediate temperature cementite within bainite, which results in a relatively softer surface and harder core in spheroidized particles. This microstructure may contribute to the good wear resistance and fatigue properties of the steel. Good agreement between DICTRA simulations and experimental composition profiles is obtained by an increase of mobility of the substitutional elements in cementite by a factor of five, compared to the mobility in the database MOBFE2.

show abstract

“…For example, this high-resolution characterization technique helps to understand diffusion of light element (e.g., boron and carbon), segregation at inter faces, gradients in chemical composition between second phase precipitate particles and their host matrix phase (Bang et al, 2015;Park et al, 2015;Seol et al, 2010Seol et al, , 2011Seol et al, , 2012Seol et al, , 2013aSeol et al, , 2013bSeol et al, , 2013cSeol et al, , 2016a. Recent significant advances of pulsedlaser APT system now enable analysis of biological material to obtain 3D spatial distributions of cellular ions (Gordon & Joester, 2011;Karlsson et al, 2015;Narayan et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

A Brief Comment on Atom Probe Tomography Applications

Seol

Kim

Park

2016

Self Cite

View full text Add to dashboard Cite

Atom probe tomography is a time-of-flight mass spectrometry-based microanalysis technique based on the field evaporation of surface atoms of a tip-shaped specimen under an extremely high surface electric field. It enables three-dimensional characterization for deeper understanding of chemical nature in conductive materials at nanometer/ atomic level, because of its high depth and spatial resolutions and ppm-level sensitivity. Indeed, the technique has been widely used to investigate the elemental partitioning in the complex microstructures, the segregation of solute atoms to the boundaries, interfaces, and dislocations as well as following of the evolution of precipitation staring from the early stage of cluster formation to the final stage of the equilibrium precipitates. The current review article aims at giving a comment to first atom probe users regarding the limitation of the techniques, providing a brief perspective on how we correctly interprets atom probe data for targeted applications.

show abstract

Atomic scale effects of alloying, partitioning, solute drag and austempering on the mechanical properties of high-carbon bainitic–austenitic TRIP steels

Cited by 135 publications

References 69 publications

Microstructures and mechanical properties of TRIP steel produced by strip casting simulated in the laboratory

Microstructures and mechanical properties of TRIP steel produced by strip casting simulated in the laboratory

On the Spheroidized Carbide Dissolution and Elemental Partitioning in High Carbon Bearing Steel 100Cr6

A Brief Comment on Atom Probe Tomography Applications

Contact Info

Product

Resources

About