© Marek Klein
IMP PAN, Gdańsk 1997-1998
ICET INTERNATIONAL CAVITATION EROSION TEST a worldwide cavitation erosion research project
sponsored exclusively |
Test Co-ordinator: |
Dr Janusz Steller, IMP PAN, steller@imp.pg.gda.pl |
Test Panel Members: |
Dr Bolesław Gireń, IMP PAN, Gdańsk, Poland | |
Test Secretary: |
Dr Bolesław Gireń, IMP PAN |
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Dr Tadeusz Krzysztofowicz, Technical University of Gdańsk, Poland | |
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Ms. Marek Klein, IMP PAN, maly@imp.pg.gda.pl |
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Dr Andrzej Lichtarowicz, University of Nottingham, U.K. | |
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Prof. Hartmut Louis, University of Hannover, Germany | ||
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Prof. Marian Mazurkiewicz University of Missouri, Rolla, U.S.A | ||
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Prof. Jaromir Noskievic Technical University of Ostrava, Czech Republic | ||
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Dr Janusz Steller, IMP PAN, Gdańsk, Poland |
compilation of data on design and operation of existing test rigs,
comparison and correlation of the damage course and cavitation resistance as-sessments
of selected groups of materials tested under different cavitation condi-tions,
establishment of relationships between the damage course and the parameters defining
cavitation load conditions,
creation of the basis for further standardisation of the methods used to assess material
resistance to cavitation damage.
No. |
Laboratory |
Contributor |
1. |
China Ship Scientific Research Centre, Wuxi, China |
Zhiye Ji |
2. |
Tsinghua University, Beijing, China |
Jitang Huang |
3. |
Technical University of Ostrava, Ostrava, |
Jaromir Noskiević |
4. |
SIGMA Research Institute1), Olomouc, Czech Republic |
Alois Koutny |
5. |
United Power Plants Co. Peitz, |
Klaus Junghanß |
6. |
University of Hannover, Hannover, Germany |
Hartmut Louis |
7. |
KSB AG, Frankenthal, Germany |
Gerd-Heinz Bauer |
8. |
Fluid Control Research Institute, Palghat, India |
M.S.Konnur |
9. |
CISE S.p.A., Milan, Italy |
Remo Martinella |
10. |
Hiroshima University, Higashi Hiroshima, Japan |
Masanobu Matsumura |
11. |
Institute of Fluid-Flow Machinery |
Janusz Steller |
12. |
University of Cape Town, Rondebosch, South Africa |
Anthony Ball |
13. |
University of Hull, Hull, England |
Robert D. James |
14. |
The City University, London, England. |
Peter A. Lush |
1) |
The SIGMA concern was dissolved by the Czechoslovakian goverment in 1990. According to Dr A.Koutny all the cavitation erosion test facilities have been taken over by the ČKD Blansko Company. |
general description |
commercial name |
Armco iron | E04 |
aluminium alloy | PA2 |
carbon steel | 45 |
acid resistant steel | 1H18N9T |
single-phase brass | M63 |
polyamide 6 plastics | Tarnamide |
The ICET programme, proposed to the Potential Test Participants, has covered tests on 6 materials listed in the table on the left. Test materials have been selected in a way providing evident differentiation between their erosion curves - it can be easily noticed that two of them (Armco iron E04 and aluminium alloy PA2) are typical reference materials used in numerous erosion tests while the next three ones (carbon steel 45, stainless steel 1H18N9T, and single phase brass M63) are structural materials commonly applied in engineering practice. All the metallic materials were acquired at the CENTROSTAL Steel Storehouse, the main distributor of metals in Poland while the polyamide 6 plastics was obtained from the CHEMIPLAST EVG in Gliwice. Chemical composition, heat treatment conditions and values of some mechanical parameters of metallic materials as well as are to be found in the ICET documents.
Almost a half of tests has been carried out using vibratory rigs. The vibration frequency of these rigs is usually close to 20 kHz which corresponds to the ASTM G-32 Standard. An exception is the IMP PAN lab with a facility of 8 kHz vibration frequency. Much wider diversity can be noticed in vibration amplitudes, sizes and mounting methods of test samples. Counter-samples are applied as a rule in 2 labs (Universities in Cape Town and Hull). Two further labs (University of Hiroshima and the Technical University of Ostrava) use stationary specimens occasionally. As it is generally known, this technique enables testing light and brittle materials. Vibrating specimen buttons are usually screwed in the horn (ASTM G-32 Standard). A specimen is screwed on the horn in the Czech Republic (Czech standard CSN-015082-76) whereas a mounting nut (Polish Standard PN-86/H-04427) is applied only in the IMP PAN.
Cavitation tunnels involved in the ICET programme show a significant differentiation in the test chamber design. Tests have been conducted in 2 tunnels with cylindrical cavitators (CSSRC and the Hohenwarte Pumped Storage Power Plant in Germany), one tunnel with a wedge cavitator (City University, London) and two tunnels with barricade and counter-barricade systems (Universities of Hiroshima and Hannover). The majority of cavitation tunnels are not used for tests of highly resistant materials.
From among four rotating disks involved in the ICET project, two facilities are of similar design. Both in the CSSRC and the SIGMA Research Institute (Olomouc, Czech Republic) cavitation has been generated by holes drilled in the disk upstream of the test samples. Cavitators in form of cylindrical bolts are applied in the IMP PAN and the KSB laboratory in Frankenthal (Germany). However, the samples are mounted at the disk in the IMP PAN and on the stagnator vanes in the KSB lab.
Cavitating jet tests have been carried out in the FCRI (Palghat, India) and at the University of Hannover. Both rigs follow exactly the design of Dr A. Lichtarowicz of the University of Nottingham.
It has been only the SIGMA Research Institute which has offered us tests carried out at a liquid impact device. As it is generally known this kind of a device was widely used in the past to assess the cavitation erosion resistance of materials.
Main parameters of the test rigs involved in the ICET programme are to be found in the ICET documents.
Test Participants have been asked to conduct erosion tests at least 2 specimens of each kind under specified steady state conditions. As usual, it was recommended to continue the tests as long as needed in order to attain the steady-state damage period. It was assumed that the data submitted on the Measurement Cards would comprise main operating parameters of the facility as well as tables of mass/volume losses in course of the test, final values of the mean and maximum depth of pits, data on microhardness distribution, photographs of damaged surfaces and their metallographic structure.
Most experimental results are available through the ICET database. Installation files of this database are attached to this document and the ICET Preliminary Report. It is assumed that this report will form a basis for discussion during the ICET Seminar to be held in 1999. The main conclusions following from the results will be summarised in the Final Report to be issued in the year 2000.
Most of the rigs were used to test all the metallic materials. However, some tests had to be abandoned. In few cases the Test Co-ordinator was not able to submit material samples of sufficient size and one cavitation tunnel appeared not suited for testing highly resistant materials, like carbon steel 45 or chromium-nickel steel 1H18N9T.
Severe difficulties occurred at numerous facilities when testing the polyamide 6 (tarnamide) plastics. Tests had to be abandoned at some vibratory rigs, including those designed according to the ASTM G-32 standard, as in view of extremely low density of the tarnamide plastics, there was no possibility to keep the horn/sample system in resonance at the prescribed frequency. Due to water absorbing properties of the tarnamide plastics no mass loss was observed during tests at low cavitation rates.
The scatter in test duration (from 30 minutes for aluminium at the liquid impact rig in Olomouc up to 365 hours for tarnamide in the cavitation tunnel in Hiroshima) can be attributed to a very wide spread of erosion rates. In spite of significant flexibility shown when selecting test duration, in numerous cases the steady-state period was not attained - sometimes due to the test having been stopped during the damage rate decrease, but quite often due to the deceleration period being immediately followed by a further rise of erosion rate.
Differences in cavitation intensities are manifested by an extremely wide range of absolute volume losses and mean depth of erosion after a comparable exposure period (e.g. 1.67 mm3 volume loss and 2.8
mm erosion depth in an aluminium specimen after a 1400 min test in the CSSRC cavitation tunnel and 1.32 cm3 volume loss and 2 mm erosion depth after a 1200 min test of the same material at the rotating disk in the IMP PAN lab).Go to EROSION - ICET database download page
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Institute of Fluid-Flow Machinery Fluid Mechanics Centre Fiszera Str. 14 80-952 Gdańsk POLAND |
Contact with:
Janusz Steller Phone: (0-048)(58) 346-08-81, 341-12-71 /138 Telex: 05122042 imp pl Fax: 341 61 44 E-mail: steller@imp.pg.gda.pl |