Understanding Defect Genesis in Steel Products: Some Revelations through Light (Optical) Microscopy and Electron-Probe Microanalysis

2007 ◽  
Vol 13 (S02) ◽  
Author(s):  
A Ray
2013 ◽  
Vol 702 ◽  
pp. 145-148 ◽  
Author(s):  
Xiao Dong Liu ◽  
Jin Zhu Zhang ◽  
Si Si Zhu

The interaction among Lanthanum, Arsenic and Iron at 1223K were studied by means of electron probe microanalysis, optical microscopy and X-ray diffraction. The result shows that the gray phase might be a ternary compound La10Fe50As40, and the binary compound LaAs and the ternary compound La10Fe50As40 are the main interaction products when the atomic ratio of La to As is 1:3. The eutectic compound Fe2As can be precipitated from ferrite with the temperature decreasing.


2007 ◽  
Vol 539-543 ◽  
pp. 3684-3689
Author(s):  
S.M.C. van Bohemen ◽  
Jilt Sietsma ◽  
Sybrand van der Zwaag

The growth mechanism of bainitic α plates in Ti-4.5Fe-6.8Mo-1.5Al, a metastable β Ti alloy, has been investigated by optical microscopy, electron probe microanalysis (EPMA) and dilatometry. The observations are compared with the transformation characteristics of primary α plates, which form at relatively high temperatures. The primary α plates form predominantly on β grain boundaries, whereas the bainitic α plates nucleate both at grain boundaries and intragranularly. It is shown that the morphological transition with decreasing temperature is associated with a change in transformation mechanism. The EPMA results show that the primary α plates are formed by a partitioning transformation. In contrast, the growth of the bainitic α plates is partitionless, followed by a post-transformation redistribution of Fe. This mechanism is similar to bainite in steel. The Fe diffusion from the supersaturated bainitic α plates to the β matrix causes the observed dilatation signal. The results of dilatometry in conjunction with optical microscopy indicate that a low misfit between the lattice structures exists, which is favourable for a partitionless transformation to occur at a low undercooling below T0.


2015 ◽  
Vol 757 ◽  
pp. 1-5
Author(s):  
Chang Jiang Liu ◽  
Qiu Juan Lv ◽  
Zhi Qing Guo ◽  
Yan Jiao Li ◽  
Jian Feng Guo

The phase equilibria in the Fe-Nb-V ternary system were investigated by means of optical microscopy, electron probe microanalysis. One isothermal section in the Fe-Nb-V ternary system at 1050 °C was firstly experimentally established. Present experimental results indicate that: (1) there is a large (Nb, V) continuous bcc solid solution; (2) there are the larger solubilities of V in the FeNb and Fe2Nb phases. The newly determined phase equilibria in this system will provide important support for the development of microalloyed steels.


2013 ◽  
Vol 546 ◽  
pp. 107-111
Author(s):  
Chang Jiang Liu ◽  
Yan Jiao Li ◽  
Zhi Qing Guo ◽  
Qiu Juan Lv ◽  
Fang Xie ◽  
...  

The phase equilibria in the Fe-Nb-V ternary system were investigated by means of optical microscopy, electron probe microanalysis. One isothermal section in the Fe-Nb-V ternary system at 900 °C was firstly experimentally established. Present experimental results indicate that: (1) there is a large (Nb, V) continuous bcc solid solution; (2) there are the larger solubilities of V in the FeNb and Fe2Nb phases. The newly determined phase equilibria in this system will provide important support for the development of microalloyed steels.


2012 ◽  
Vol 460 ◽  
pp. 103-106
Author(s):  
Sheng Tao Dou ◽  
Jin Zhu Zhang ◽  
Jun Huang

The interaction among Cerium, Arsenic and Iron at high temperature in a pressure-tight reactor were studied by means of electron probe microanalysis, optical microscopy and X-ray diffraction to understand what compounds could be developed and how about their stability chemically should be. The result shows that the binary compound CeAs is the main product on condition that the atomic ratio of Cerium to Arsenic is 2:1. There are some Fe2Ce, Ce4As3 and Fe17Ce2 compounds developed meanwhile. The amount of Fe17Ce2 phase by the base of steel increased with time prolonging at high temperature


2020 ◽  
Vol 213 ◽  
pp. 02017
Author(s):  
Chengjun Jiang ◽  
Wei Wang ◽  
Xiaohui Zou ◽  
Jifeng Wang

The microstructure, micrograph of the fracture sections and the alloy elements distribution of the fractured flange-connecting bolts of 3# circulating pump in a power plant were analyzed by the scanning electron microscopy, the optical microscopy and the electron probe microanalysis. The results showed that the failed bolts’ material is not the design material, and failure of the bolts is due to the stress corrosion crack propagation of the bolts’ austenitic material by chloride ions in seawater.


2021 ◽  
Vol 2103 (1) ◽  
pp. 012072
Author(s):  
E A Silantieva ◽  
M V Zamoryanskaya ◽  
B E Burakov

Abstract Crystals of xenotime-structured phosphates doped with erbium had been grown from molybdate flux at a temperature 1220 ° C followed by slow cooling. The crystals synthesized had been studied using X-ray diffraction and electron probe microanalysis in combination with optical microscopy and luminescence studies.


Author(s):  
Claude Lechene

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.


Author(s):  
R. Packwood ◽  
M.W. Phaneuf ◽  
V. Weatherall ◽  
I. Bassignana

The development of specialized analytical instruments such as the SIMS, XPS, ISS etc., all with truly incredible abilities in certain areas, has given rise to the notion that electron probe microanalysis (EPMA) is an old fashioned and rather inadequate technique, and one that is of little or no use in such high technology fields as the semiconductor industry. Whilst it is true that the microprobe does not possess parts-per-billion sensitivity (ppb) or monolayer depth resolution it is also true that many times these extremes of performance are not essential and that a few tens of parts-per-million (ppm) and a few tens of nanometers depth resolution is all that is required. In fact, the microprobe may well be the second choice method for a wide range of analytical problems and even the method of choice for a few.The literature is replete with remarks that suggest the writer is confusing an SEM-EDXS combination with an instrument such as the Cameca SX-50. Even where this confusion does not exist, the literature discusses microprobe detection limits that are seldom stated to be as low as 100 ppm, whereas there are numerous element combinations for which 10-20 ppm is routinely attainable.


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