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1500 |
Experimental 1 Mw boiler for corrosion experiments at KEMA (the Netherlands). With this boiler a very extensive research was performed on boiler or heat flux corrosion, erosion-corrosion and even experiments at super-critical conditons. (foto KEMA, ref 11, 13, 21, 23, 27, 28, 40, 47 and 61). |
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1501 |
Deposit phenomena in the test tubes under heat flux conditions with an inlet steam fraction of 0.58 up to 0.74; annular flow conditions. (ref 11). |
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1503 |
Pockshape deposits (resulting from the nucleate boiling process) show often a donut shape. Even the flow direction of the water can be noticed. (in both pictures from left to right). (foto KEMA, ref 61). |
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1504 |
Top foto: Pockshape deposits formed under plug-flow and nucleate boiling conditions. Foto below: Underneath the deposit and the thin magnetite layer (see arrow) pitting corrosion is started. (foto KEMA, ref 61). |
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1505 |
The 3 types of deposits under different heat flux conditions: a) pimples, b) feather-shape deposits and c) homogeneous deposits. (foto KEMA, ref 20,61). |
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1506 |
Pockshaped deposits as a result of nucleate boiling in two phase flow condition in relative good boiler water. (foto KEMA, ref 11). |
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1507 |
SEM picture of the pock shown in foto 1503. (foto KEMA, refd 61). |
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1508 |
SEM picture of the pock shown in foto 1504. (foto KEMA, refd 61). |
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1509 |
SEM picture of detail of the pock shown in foto 1508. (foto KEMA, refd 61). |
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1510 |
SEM picture of detail of the pock shown in foto 1507. (foto KEMA, refd 61). |
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1514 |
Scanning electron microscope picture of the homogeneous deposit layer with a depositfree path behind an obstacle. See foto 1505 case c. (foto KEMA, ref 11). |
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1527 |
SEM Picture of a pock in a boiler tube. (foto KEMA, ref 61) |
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1528 |
SEM Picture of a detail of foto 1527. (foto KEMA, ref 61) |
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1529 |
Dehydrated rust-layers on concave places of the rough boiler tubes in the test facility of KEMA. The rust has been formed during the many shutdowns. (foto KEMA, ref 61). |
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1530 |
SEM picture of the dehydrated rust-layers in foto 1525. (foto KEMA, ref 61). |
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1548 |
Pockshaped deposits on a Zircaloy fuel element in a Boiling Water Reactor. Nodular corrosion takes plac at the pellet interfaces. (foto KEMA, ref 61). |
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1550 |
Model for the formation of salt deposits in a porous layer of iron oxides. The salts are conducted to
the bottom of the steam tunnel, where they precipitate when their solubility is exceeded. (foto KEMA, ref 11). |
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1553 |
Foto's a and b: SEM pictures of the porous oxide layer. Steam chimneys are present. Foto's c and d: Optical microscopic pictures of the cross sections . (foto KEMA, ref 13, 61). |
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1554 |
Two tube halves: (a) heat irradiated part, and (b) nonirradiated part. The loose oxide layer on both tube halves has been removed by water rinsing. On tube part with heat flux (a) a network of salts is noticed under the loose oxide layer. (foto KEMA, ref 13, 61). |
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1555 |
Longitudinal section through tube 57/ 145/ 99. On the top of the 1 to 2 micron thick magnetite layer are a dark isotropic salt layer (40 microns thick), an anisotropic salt layer (80 microns thick) and a porous layer of hematite and magnetite. Right: Scanning electron microscopic picture showed that the elements Mg, S and Fe were found in the dark salt layer. In the outer layer is, in addition, Ca found. (foto KEMA, ref 11). |
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1556 |
Scanning electron microscopic picture showed that the elements Mg, S and Fe were found in the dark salt layer. In the outer layer is, in addition, Ca found. (foto KEMA, ref 11) |
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1557 |
Detailed pictures of the dark salt layer on top of the thin magnetite layer in tube 57/145/98-100. The pearlite structure of the steel can be recognised in the dark-grey salt layer, which points to attack of the magnetite by the salt layer.(foto KEMA, ref 11). |
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