scholarly journals Novel Etching Technique for Delineation of Prior-Austenite Grain Boundaries in Low, Medium and High Carbon Steels

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3296
Author(s):  
Richard Thackray ◽  
Eric J. Palmiere ◽  
Omar Khalid
Keyword(s):  
Grain Boundaries ◽  
Prior Austenite ◽  
Picric Acid ◽  
High Carbon Steel ◽  
Sodium Dodecyl ◽  
Carbon Steels ◽  
Sodium Dodecylbenzene Sulfonate ◽  
High Carbon ◽  
Austenite Grain ◽  
Prior Austenite Grain

The etching of prior austenite grain boundaries in martensite for detailed quantitative metallography of low to high carbon steel has been carried out using aqueous solutions of picric acid containing different wetting agents. The choice of wetting agent was shown to be dependent on the carbon content of the steel, with sodium dodecyl sulfate (SDS) being more suitable for use with low and medium carbon steels, whereas sodium dodecylbenzene sulfonate (SDBS) was shown to be more appropriate for high carbon steels. It is also recommended that, for a particular steel, a variety of temper treatments should be carried out in order to reveal grain boundaries, particularly where more detailed results than simple grain size measurements are required. Finally, the use of dummy specimens prior to etching of the real samples was shown to reduce the need for re-polishing and re-etching of the samples.

Visualization of Prior Austenite Grain Boundaries in Low-Carbon Steels

2021 ◽  
Vol 58 (11) ◽  
pp. 697-714
Author(s):  
M. Böcker ◽  
M. Steinbacher ◽  
R. Fechte-Heinen
Keyword(s):  
Grain Boundaries ◽  
Prior Austenite ◽  
Microalloyed Steel ◽  
Picric Acid ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Austenite Grain ◽  
Carbon Microalloyed ◽  
Prior Austenite Grain

Abstract Knowledge of the size of the prior austenite grain is of key importance. If abnormal grain growth occurs during austenitization, the resultant inhomogeneous microstructure may negatively affect the strength and toughness properties of the final product. The visualization of prior austenite grain boundaries with an etchant based on picric acid has been applied for years. Despite this long-time experience, it is often challenging to achieve sufficiently good visualization of prior austenite grain boundaries in many steel grades, especially low-carbon steels. This work will study the effect of the cooling rate from austenitizing temperature down to room temperature, of the subsequent tempering treatment and the etchant on the visualization of prior austenite grain boundaries in a low-carbon microalloyed steel. All these parameters have an impact on the etching result. A suitable etchant for the visualization of prior austenite grain boundaries in a low-carbon microalloyed steel could be found.

The Effect of Boron Addition on Precipitation and Hot Ductility of 1.5Mn-0.1Nb-Ti Carbon Steels in As-Cast Condition

2016 ◽  
Vol 879 ◽  
pp. 990-995 ◽  
Author(s):  
Jacek Komenda ◽  
David Martin ◽  
Johan Lönnqvist
Keyword(s):  
Grain Boundaries ◽  
Base Composition ◽  
Prior Austenite ◽  
Carbon Steels ◽  
Hot Ductility ◽  
Austenite Grain ◽  
Reduction In Area ◽  
Cast Condition ◽  
Prior Austenite Grain ◽  
Start Temperature

Twelve experimental steels with a base composition 1.5wt% Mn, 0.01 wt% V and 0.1 wt% Nb and varying C (0.05, 010 and 0.20 wt%), Ti (20 – 260 ppm) and B (0 – 100 ppm) contents have been systematically examined to quantify the effects of composition on precipitation behavio-ur and hot ductility during simulated continuous casting conditions. Nb-rich precipitates were present in the alloys with 0.10 wt-% C and 0.20 wt-% C. Alloys with 0.05, 010 and 0.20wt% C contained 50 – 100 nm size Ti-Nb carbonitrides. Boron was bound in 20 – 100 nm size boronitrides located in prior austenite grain boundaries. A Gleeble 3800 was used to study hot ductility and strain induced precipitation processes in the alloys. Alloys without B and Ti additions exhibited poor hot ductility at 850°C and 950°C, whereas the 0.05 wt-% C and 0.10 wt-% C alloys showed improved hot ductility (reduction in area 40-50%) by the addition of either >50 ppm B or 250 ppm Ti. The 0.2 wt-% C alloys showed no improvement from B or Ti additions. Examination of fracture surfaces of hot ductility specimens showed that boronitrides were located at prior austenite grain boundaries in alloys containing 80 – 100 ppm of B. Compression-relaxation tests showed that alloying with boron caused a noticeable decrease of the start temperature of strain-induced precipitation in the alloys.

scholarly journals Delineating Prior Austenite Grain Boundaries in Carbon Steels

2011 ◽  
Vol 17 (S2) ◽  
pp. 1038-1039
Author(s):  
S Lawrence
Keyword(s):  
Grain Boundaries ◽  
Prior Austenite ◽  
Carbon Steels ◽  
Austenite Grain ◽  
Prior Austenite Grain

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

A quantitative atom probe study of the Nb excess at prior austenite grain boundaries in a Nb microalloyed strip-cast steel

2012 ◽  
Vol 60 (13-14) ◽  
pp. 5049-5055 ◽  
Author(s):  
Peter J. Felfer ◽  
Chris R. Killmore ◽  
Jim G. Williams ◽  
Kristin R. Carpenter ◽  
Simon P. Ringer ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Prior Austenite ◽  
Cast Steel ◽  
Atom Probe ◽  
Austenite Grain ◽  
Strip Cast ◽  
Prior Austenite Grain

Nb segregation at prior austenite grain boundaries and defects in high strength low alloy steel during cooling

2017 ◽  
Vol 115 ◽  
pp. 165-169 ◽  
Author(s):  
Xianglong Li ◽  
Ping Wu ◽  
Ruijie Yang ◽  
Shoutian Zhao ◽  
Shiping Zhang ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Alloy Steel ◽  
Prior Austenite ◽  
High Strength ◽  
Low Alloy Steel ◽  
Austenite Grain ◽  
Prior Austenite Grain

Cavitation control in steels of high residual element content

1980 ◽  
Vol 295 (1413) ◽  
pp. 305-305 ◽  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Prior Austenite ◽  
Low Alloy Steels ◽  
Boundary Zone ◽  
Austenite Grain ◽  
Alloy Steels ◽  
Austenite Grain Boundary ◽  
Prior Austenite Grain ◽  
Transverse Boundary

The cavitational mode of failure of prior austenite grain boundaries in bainitic creep-resisting low alloy steels is now well established as a principal factor in the high incidence of cracking problems which has developed on modern power plant in recent years. The microstructural features dominating the cavitation process at the reheat temperature in a ½CMV bainitic steel of high classical residual level have been determined. The prior austenite grain boundaries become zones of comparative weakness ca . 1 pm thick at 700 °C and are incapable of sustaining significant shear loads. Deformation is therefore initiated by a relaxation of load, through a process of prior austenite grain boundary zone shear, from inclined to transverse boundaries such that a concentration of normal stress develops across the latter. The overall deformation is thereafter determined by cavitation of the transverse boundary zones, the necessary inclined boundary displacements being accommodated by further grain boundary zone shear. Transverse boundary cavitation is shown to be an essentially time-independent process of localized ductile microvoid coalescence resulting from the plastic deformation of the boundary zone.

scholarly journals Orientation Distribution of Proeutectoid Ferrite Nucleated at Prior Austenite Grain Boundaries in Vanadium-added Steel.

2002 ◽  
Vol 42 (11) ◽  
pp. 1321-1323 ◽  
Author(s):  
Jae-Young Cho ◽  
Dong-Woo Suh ◽  
Joo-Hee Kang ◽  
Hu-Chul Lee
Keyword(s):  
Grain Boundaries ◽  
Prior Austenite ◽  
Orientation Distribution ◽  
Austenite Grain ◽  
Proeutectoid Ferrite ◽  
Prior Austenite Grain

The effects of prior austenite grain boundaries and microstructural morphology on the impact toughness of intercritically annealed medium Mn steel

2017 ◽  
Vol 122 ◽  
pp. 199-206 ◽  
Author(s):  
Jeongho Han ◽  
Alisson Kwiatkowski da Silva ◽  
Dirk Ponge ◽  
Dierk Raabe ◽  
Sang-Min Lee ◽  
...  
Keyword(s):  
Impact Toughness ◽  
Grain Boundaries ◽  
Prior Austenite ◽  
Austenite Grain ◽  
Medium Mn Steel ◽  
Microstructural Morphology ◽  
The Impact ◽  
Mn Steel ◽  
Prior Austenite Grain
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