Chapter 2—Extraction, Replica Techniques

2009 ◽  
pp. 19-19-10
Author(s):  
Keyword(s):  
Extraction Replica

scholarly journals Analysis of Recrystallization and Strain-Induced Precipitation on High Nb- and N-Bearing Austenitic Stainless Steel

2014 ◽  
Vol 922 ◽  
pp. 700-705 ◽  
Author(s):  
Mariana B.R. Silva ◽  
J. Gallego ◽  
Jose María Cabrera ◽  
O. Balancin ◽  
Alberto Moreira Jorge
Keyword(s):  
Thermomechanical Processing ◽  
Extraction Replica ◽  
Carbon Extraction Replica ◽  
Thin Foils ◽  
Transmission Electron ◽  
Hot Torsion ◽  
Deformation Pass ◽  
Mechanical Properties And Corrosion ◽  
Multiple Deformation ◽  
Soaking Temperature

The mechanical properties and corrosion resistance of stainless steels are due to the combined effect of chemical composition and thermomechanical processing. The objective of this study was to investigate the interaction precipitation-recrystallization of an austenitic steel with high additions of nitrogen and niobium through continuous-cooling multiple deformation hot-torsion tests. Samples were heated up to a soaking temperature of 1250oC and kept at this temperature for 5 minutes, and then deformed during cooling. The deformation pass was 0.3 with a strain rate of 1 s-1and interpass times of 20 or 50 s. The evolution of the microstructure was investigated by optical, EBSD and transmission electron microscopy, using thin foils and carbon extraction replica samples. The results showed that some precipitates were not dissolved after reheating and the presence of niobium-and chromium-rich particles after processing was confirmed. The strain accumulation with the interpass time of 20 s yielded finer precipitation and improved grain refinement than observed after 50 s. Some interaction of the precipitates with dislocations and grain boundary could be evidenced.

Carbo-Nitride Precipitation in Tempered Martensite - Computer Simulation and Experiment

2012 ◽  
Vol 706-709 ◽  
pp. 1586-1591 ◽  
Author(s):  
Sabine Zamberger ◽  
Ernst Kozeschnik
Keyword(s):  
Computer Simulation ◽  
Precipitation Behavior ◽  
Tempered Martensite ◽  
Extraction Replica ◽  
Transmission Electron ◽  
Simulation And Experiment ◽  
Precipitate Microstructure ◽  
Means Of Transmission ◽  
Quenched And Tempered Steel ◽  
Good Agreement

In the present work, the precipitation behavior of a V-microalloyed, quenched and tempered steel with 0.3wt % C is investigated experimentally and by computer simulation. The specimens are analyzed by means of transmission electron microscopy using selected area diffraction (SAD) and energy dispersive x-ray spectroscopy (EDX). The analysis is done on electropolished foils and on extraction replica. The numerical simulation is performed with the thermokinetic software package MatCalc, where the precipitation kinetics is examined for the experimentally applied thermo-mechanical cycles. Good agreement between experiment and simulation is obtained and the experimentally observed precipitate microstructure can be well explained on the basis of these simulations.

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.

Electrolytic Extractions of Precipitates From Steel Alloys

1985 ◽  
Vol 43 ◽  
pp. 168-169
Author(s):  
W. H. Smith
Keyword(s):  
Structural Information ◽  
Vacuum Filter ◽  
Replica Technique ◽  
Extraction Replica ◽  
Electrolytic Extraction ◽  
Acid Cleaning ◽  
Surrounding Matrix ◽  
The Matrix ◽  
Method Of Extraction

During aging of an iron based alloy, the degree of preparation has significant effects on the properties of the alloy. Long-term heat treatments can produce rather large precipitates. In order to obtain compositional and/or structural information from these large precipitates, it is often necessary to examine them in the absence of the surrounding matrix. However it has been found that the extraction replica technique is reliable only for particles 1 μn in size or less. Any larger particle tends to stay embedded in the matrix. We have found electrolytic extraction from the this bulk to be the only reliable way to obtain precipitate particles larger than 1 um. By modifying a gravimetric-vacuum filter assembly, a new method of extraction has been developed, eliminating the time consuming and laborious steps of centrifuging the electrolyte, retrieval of precipitates from test tubes, vacuum drying, and acid cleaning of glassware.

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