Analyzing Boron in 9-12% Chromium Steels Using Atom Probe Tomography
Artikel i vetenskaplig tidskrift, 2019

Microscopy Society of America 2019. Small additions of boron can remarkably improve the long-term creep resistance of 9-12% Cr steels. The improvement has been attributed to boron segregation to grain boundaries during quenching, and subsequent boron incorporation into certain families of precipitates during tempering. However, the detailed mechanisms are not yet fully understood. Atom probe tomography (APT) is an excellent technique for gaining insights into boron distribution, however, in order to acquire accurate analysis of boron in 9-12% Cr steels using APT, there are several key challenges. In order to better understand and address these challenges, we developed a novel method for site-specific APT specimen preparation, which enables convenient preparation of specimens containing specifically selected grain boundaries positioned approximately perpendicular to the axis of the APT tip. Additionally, when analyzing boron at boundaries and in carbides (as diluted solute) and borides, a widening of the profile of boron distribution compared to other elements was repeatedly observed. This phenomenon is particularly analyzed and discussed in light of the evaporation field of different elements. Finally, the possible effects of detector dead-time on quantitative analysis of boron in metal borides are discussed. A simple method using 10B correction was used to obtain good quantification.

non-equilibrium segregation

custom-made specimen holder

quantification

borides

TKD

prior austenite grain boundaries

carbides

equilibrium segregation

precipitates

Författare

Irina Fedorova

Danmarks Tekniske Universitet (DTU)

F. B. Grumsen

Danmarks Tekniske Universitet (DTU)

John Hald

Danmarks Tekniske Universitet (DTU)

Hans-Olof Andrén

Chalmers, Fysik, Materialens mikrostruktur

Fang Liu

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Microscopy and Microanalysis

1431-9276 (ISSN) 1435-8115 (eISSN)

Vol. 25 2 462-469

Ämneskategorier

Annan kemi

Annan materialteknik

Metallurgi och metalliska material

DOI

10.1017/S1431927618015726

Mer information

Senast uppdaterat

2019-05-14