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1.
In this study a new approach to the online monitoring of the Al depth profile of hot-dip galvanised sheet steel is presented,
based on laser-induced breakdown spectroscopy (LIBS). The coating composition is measured by irradiating the traversing sheet
steel with a series of single laser bursts, each at a different sheet steel position. An ablation depth in the same range
as the coating thickness (about 10 μm) is achieved by applying a Nd:YAG laser at 1064 nm in collinear double-pulse and triple-pulse
mode. The ablation depth is controlled by adjusting the burst energy with an external electro-optical attenuator. A fingerprint
of the depth profile is gained by measuring the LIBS signals from zinc, aluminium and iron as a function of the burst energy,
and by post-processing the data obtained. Up to three depths can be sampled simultaneously with a single laser burst by measuring
the LIBS signals after each pulse within the laser burst. A concept for continuously monitoring the Al depth profile during
the galvanising process is presented and applied to different hot-dip galvanised coatings. The method was tested on rotating
sheet steel disks moving at a speed of up to 1 m/s. The potential and limitations of the new method are discussed. 相似文献
2.
N. Pistofidis G. Vourlias E. Pavlidou K. Chrissafis G. Stergioudis E. K. Polychroniadis D. Tsipa 《Journal of Thermal Analysis and Calorimetry》2006,86(2):417-422
The effect of Pb
and Sn on the structure of zinc hot-dip galvanized coatings on steel wires
is examined. The coating quality is often low because of the Sandelin effect.
An improvement could be expected if 1.0 mass% Pb is added to the Zn bath.
In this case the η phase formation is enhanced, while the coating thickness
is reduced. The Sn addition at the same concentration promotes the formation
of the η phase but it does not affect the thickness. 相似文献
3.
Francesco Rosalbino Giorgio Scavino Giovanni Mortarino Emma Angelini Giancarlo Lunazzi 《Journal of Solid State Electrochemistry》2011,15(4):703-709
The corrosion performance of a new industrial Cr(III)-based conversion coating on zinc galvanized FeP04 steel for the automotive
industry was studied. For comparison, the zinc galvanized steel submitted to a Cr(VI)-based passivation treatment was also
examined. The corrosion behavior was assessed by means of potentiodynamic polarization and electrochemical impedance spectroscopy
measurements in aerated 0.1 M NaCl solution. The behavior of untreated zinc galvanized FeP04 steel in aerated 0.1 M NaCl solution
was also studied. The results obtained indicate that with the same thickness, the coating generated in the Cr(III) treatment
bath exhibits better corrosion properties compared to the coating formed in the Cr(VI) treatment bath. The difference in the
corrosion protection given by the two conversion coating types can be ascribed to the difference in the chromium content and
coating composition. 相似文献
4.
Ricardo N. Garavaglia Rubén E. Rodríguez D. A. Batistoni 《Fresenius' Journal of Analytical Chemistry》1998,360(6):683-688
An evaluation of butanol-1 as dilution solvent for the determination of boron (B) and phosphorus (P) in lubricating oils
by inductively coupled plasma-atomic emission spectrometry (ICP-AES) has been performed. Standard solutions of boric acid
and tri-n-butyl phosphate (TBP) in butanol were employed as calibrants for B and P, respectively. Solutions of phosphoric
acid and tris(2-ethylhexyl)phosphate (TEHP) in butanol were also tested as possible P standards. Increased concentrations
of oil in the sample in the range of 0 to 20% showed no significant effects on B and P emission intensities indicating that
matrix matching is not required for lubricating oils of about 2–15 cPoise. Detection limits in absence of spectral interferences
were 0.06 μg B/g oil and 2 μg P/g oil. Overall estimated precision was 2.5% for B concentrations above 4 μg/g oil, and 6.5%
for P concentrations above 20 μg/g oil. We evaluated the performance of a high resolution scanning spectrometer for mitigating
the effects of overlapping spectral interferences from iron (Fe) and copper (Cu) on B and P emission lines. An interference
from Fe 249.782 nm on the primary B line at 249.773 nm is observed for Fe concentrations higher than 100 μg/g oil, but a secondary
B line at 249.678 nm is completely resolved from Fe 249.653 nm. In the case of P 213.618 nm, a contribution of the right wing
of a Cu line at 213.598 nm generates a signal equivalent to P 18 μg/g oil for Cu 1000 μg/g oil.
Received: 25 June 1997 / Revised: 16 September 1997 / Accepted: 7 October 1997 相似文献
5.
Ricardo N. Garavaglia Rubén E. Rodríguez D. A. Batistoni 《Analytical and bioanalytical chemistry》1998,360(6):683-688
An evaluation of butanol-1 as dilution solvent for the determination of boron (B) and phosphorus (P) in lubricating oils
by inductively coupled plasma-atomic emission spectrometry (ICP-AES) has been performed. Standard solutions of boric acid
and tri-n-butyl phosphate (TBP) in butanol were employed as calibrants for B and P, respectively. Solutions of phosphoric
acid and tris(2-ethylhexyl)phosphate (TEHP) in butanol were also tested as possible P standards. Increased concentrations
of oil in the sample in the range of 0 to 20% showed no significant effects on B and P emission intensities indicating that
matrix matching is not required for lubricating oils of about 2–15 cPoise. Detection limits in absence of spectral interferences
were 0.06 μg B/g oil and 2 μg P/g oil. Overall estimated precision was 2.5% for B concentrations above 4 μg/g oil, and 6.5%
for P concentrations above 20 μg/g oil. We evaluated the performance of a high resolution scanning spectrometer for mitigating
the effects of overlapping spectral interferences from iron (Fe) and copper (Cu) on B and P emission lines. An interference
from Fe 249.782 nm on the primary B line at 249.773 nm is observed for Fe concentrations higher than 100 μg/g oil, but a secondary
B line at 249.678 nm is completely resolved from Fe 249.653 nm. In the case of P 213.618 nm, a contribution of the right wing
of a Cu line at 213.598 nm generates a signal equivalent to P 18 μg/g oil for Cu 1000 μg/g oil.
Received: 25 June 1997 / Revised: 16 September 1997 / Accepted: 7 October 1997 相似文献
6.
M. S. Trtica B. M. Gaković B. B. Radak 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(9):1429-1432
Interactions of a transversely excited atmospheric (TEA) CO2 laser, pulse duration ∼2 μs (initial spike FWHM ∼120 ns), with polycrystalline titanium nitride (TiN) coatings deposited
on high-quality steel (AISI 316 or M2) were studied. The experiments were carried out in a regime of high laser energy densities:
25, 48, and 50 J/cm2. The energy absorbed from the laser beam was partially converted to thermal energy and the effects of the TiN coating thickness
on the morphological changes were considered. The morphological features and processes that accompany the interaction can
be summarized as follows: (i) exfoliation of the TiN coating in the central zone of the irradiated area (for coating thickness
of 1 μm) or appearance of grainy structure (for coating thicknesses 3 and 10 μm); (ii) appearance of hydrodynamic changes
in the surrounding peripheral zone; and (iii) appearance of plasma in front of the target during sample irradiation.
The text was submitted by the authors in English. 相似文献
7.
辉光放电光谱法分析镀锌钢板 总被引:6,自引:1,他引:6
介绍了利用辉光放电光谱法分析不同种类的热镀锌板和电镀锌板的镀层定量分析;在锌铁合金化热镀锌板上界面定量计算方法的设计;锌铁合金化热镀锌板表面问题的发现。试验结果表明,辉光放电光谱法是配合镀锌板产品质量控制、研究开发的一种有效的分析手段。 相似文献
8.
Löbe A Vrenegor J Fleige R Sturm V Noll R 《Analytical and bioanalytical chemistry》2006,385(2):326-332
The sensitivity of laser-induced breakdown spectroscopy of solid samples depends on the number of ablated and excited analytes.
Laser ablation of solid samples can be enhanced by using collinear multiple laser pulses, for example double or triple pulses,
rather than single laser pulses with the same total laser pulse energy. The ablation rates and the plasma conditions are affected
by the ambient gas. In this study laser ablation was examined by varying the interpulse separation of the multiple pulses,
within double and triple-pulse bursts, and the gas mass density at constant gas pressure. Different ambient gases and gas
mixtures consisting of argon, oxygen, and nitrogen were used to study their effect on ablation rates. In a pure argon atmosphere
(99.999% v/v Ar) the ablation burst number required to penetrate a steel plate of thickness 100 μm is reduced by a factor of approximately
six by use of triple-pulse bursts with a symmetric interpulse separation of 15 μs rather than single pulses with the same
total burst energy of 105 mJ. For double and single pulses the factors are 1.6 for Ar and 2.8 for synthetic air. Analyte lines
are 4 to 8 times more intense if an argon atmosphere, rather than air, is used. 相似文献
9.
《Materials Chemistry》1982,7(2):285
The dissolution of galvanized steel in acid solution was followed by thermometric, potential-time and weight loss techniques. In HCl and H2SO4, only the zinc coat is attacked, while in HNO3, curves representing stepwise dissolution of the coating layer and steel base are obtained. The time, t, required for complete dissolution of the zinc coat as measured by the three techniques is comparable.Dissolution of steel pieces of different coating thickness has been examine in 1 M H2SO4 by the thermometric method. Starting from the initial temperature, Ti, t, then temperature of the system rises to attain a maximum value, Tm, after a time, t, then decreases. Up to 6 g/dm2 coating thickness, both ΔT(Tm − Ti) and t vary linearly with coating thickness. The results suggest the thermometric method for the determination of coating thickness of galvanized steel. 相似文献
10.
T. Ahbe K. Hasche K. Herrmann K.-P. Hoffmann K. Thiele 《Analytical and bioanalytical chemistry》1999,365(1-3):55-58
Investigations on the traceability of coating thickness measurements to the national standard of length were carried out by
topographical and lateral methods. The topographical method used an interference-optical microscope and a modified scanning
force microscope to measure the coating thickness as the height of a step on partially coated samples. For the lateral method,
a scanning electron microscope was equipped with additional components to measure the coating thickness on cross sections
as the distance of material boundary lines. Standards with a coating thickness of about h = 10 nm to 50 μm may be calibrated.
The achievable uncertainty depended strongly on the specimen preparation and the specimens themselves.
Received: 14 January 1999 / Revised: 22 March 1999 / Accepted: 23 March 1999 相似文献
11.
A highly sensitive and very simple spectrophotometric flow-injection analysis (FIA) method for the determination of iron(III)
at low concentration levels is presented. The method is based on the measurement of absorbance intensity of the red complex
at 410 nm formed by iron(III) and diphenylamine-4-sulfonic acid sodium salt (DPA-4-SA). It is a simple, highly sensitive,
fast, and low cost alternative method using the color developing reagent DPA-4-SA in acetate buffer at pH 5.50 and the flow-rate
of 1 mL min−1 with the sample throughput of 60 h−1. The method provided a linear determination range between 5 μg L−1 and 200 μg L−1 with the detection limit (3S) of 1 μg L−1 of iron(III) using the injection volume of 20 μL. FIA variables influencing the system performance were optimized. The amount
of iron(III) and total iron in river and seawater samples was successfully determined. Repeatability of the measurements was
satisfactory at the relative standard deviation of 3.5 % for 5 determinations of 10 μg L−1 iron(III). The accuracy of the method was evaluated using the standard addition method and checked by the analysis of the
certified material Std Zn/Al/Cu 43 XZ3F. 相似文献
12.
G. Vourlias N. Pistofidis K. Chrissafis E. Pavlidou G. Stergioudis 《Journal of Thermal Analysis and Calorimetry》2008,91(2):497-501
A zinc deposition method that could be used instead hot-dip galvanizing is pack cementation, where the substrate is heated
immersed in a powder mixture containing Zn and a halide activator (NH4Cl). In the present work the mechanism of this process is examined, along with the effect of temperature and heating time
on the coating thickness and structure. For this purpose the coating was deposited and characterized with SEM, while the deposition
mechanism was investigated with DSC. From the above examination it was deduced that the deposition of Zn takes place with
a multiple-step mechanism, which involves several reactions in the gaseous phase including the formation of volatile zinc
halides and finally the diffusion of zinc in the crystal lattice of the ferrous substrate. This procedure is accomplished
at about 300°C and leads to the growth of a coating composed by two layers referring to Γ and δ phase of the Fe-Zn system.
The coating deposition rate seems to be controlled by the zinc diffusion as its determination at 300 and 350°C showed, where
it was deduced that the coating thickness is a linear function of the square root of heating time. However the coating structure
is not affected by the heating time and temperature. 相似文献
13.
M. Beran 《Journal of Radioanalytical and Nuclear Chemistry》1979,51(1):173-177
Ultrathin zirconium phosphate layers about 300–600 nm in thickness have been prepared on stainless steel supports. The adherence
and homogeneity of the layers are sufficient. The adsorption properies in respect to alpha-emitters (239Pu and241Am) have been studied. The adsorption equilibrium is reached in half an hour and a total capacity of about 3–4 μg Pu has been
estimated. Alpha-spectrometric properties of the samples have been evaluated by measuring the half-width of the239Pu main peak, which is close to the resolution ability of the detector. 相似文献
14.
Laser-induced breakdown spectroscopy (LIBS) is applied for depth profile analysis of different thicknesses of copper foils attached on steel and aluminum substrates. In order to account interfacial effects, depth profile analysis of copper coated on steel is also carried out. Experiments are done at ambient air and at two different wavelengths of 266 and 1064 nm of a Nd:YAG laser with pulse durations of 5 ns. A three-dimensional model of multi-pulse laser ablation is introduced on the base of normal evaporation mechanism and the simulation results are compared with the experiments. A normalized concentration (CN) is introduced for determination of interface position and results are compared with the usually used normalized intensity (IN). The effect of coating thickness on average ablation rate and resolution of depth profiling are examined. There is a correlation coefficient higher than 0.95 between the model and experimental depth profiles based on the CN method. Depth profile analysis on the base of CN method shows a better depth resolution in comparison with IN method .Increase in the layer thickness, leads to a decrease in the ablation rate. 相似文献
15.
A simple and rapid flow-injection spectrophotometric method for the determination of iron(III) and total iron is proposed.
The method is based on the reaction between iron(III) and O-acetylsalicylhydroxamic acid (AcSHA) in a 2 % methanol solution resulting in an intense violet complex with strong absorption
at 475 nm. Optimum conditions for the determination of iron(III) and the interfering ions were tested. The relative standard
deviation for the determination of 5 μg L−1 iron(III) was 0.85 % (n = 10), and the limit of detection (blank signal plus three times the standard deviation of the blank) was 0.5 μg L−1, both based on the injection volumes of 20 μL. The method was successfully applied in the determination of iron(III) and
total iron in water and ore samples. The method was verified by analysing a certified reference material Zn/Al/Cu 43XZ3F and
also by the AAS method. 相似文献
16.
Thomas Hübert Jack Schwarz Bernd Oertel 《Journal of Sol-Gel Science and Technology》2006,38(2):179-184
The aluminium oxide films on austenitic steel are prepared from sols of re-dispersed boehmite nano powders in water. After
dip-coating of the sol, a heat treatment including drying, calcination and annealing in vacuum at temperatures up to 1100°C
is performed to obtain crack-free coatings of a thickness up to 6 μm. XRD measurements detect α- and γ-alumina, a TiOx-phase at the metal/coating interface and a gradient of phase formation in the coating. The strong adhesion on the substrates
is due to the layered assembly and gradient composition of the coating caused by an inter-diffusion of metal cations and oxygen
in the metal/oxide interface during heat treatment. Residual stress measurements by X-rays result in compressive stresses
of 2–4 GPa in the alumina coatings. The pin-on-disc test shows a remarkable improvement of wear resistance obtained by sol-gel
coatings. The α-alumina content and the compressive stress of the coatings correlate with wear resistance of the coatings. 相似文献
17.
M. Trtica V. F. Tarasenko B. Gakovi? A. N. Panchenko B. Radak J. Stasi? 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(9):1577-1581
Morphology effects induced during interaction of μs- (Transversely Excited Atmospheric (TEA) CO2 laser) or ns- (HF laser) pulses with titanium nitride (TiN) coating, deposited on austenitic stainless steel AISI 316, were
studied. Experiments were carried out in regime of focused laser beam in air at atmospheric pressure. The used laser fluences
were found to be sufficient for inducing intensive surface modifications of the target. The energy absorbed from the CO2 as well as HF laser beam is mainly converted into thermal energy, causing different effects like ablation, appearance of
hydrodynamic features, etc. Morphology characteristics obtained during ns-pulses irradiation (HF laser) were different to
those initiated by μs-pulses (TEA CO2 laser). The changes on the target surface in form of massive resolidifed droplets and crown-like structures were observed
only for ns- (HF laser) pulses. It was found that these effects are a consequence of higher temperature and better coupling
of the HF laser radiation with the target. Recent investigations of ps-Nd:YAG laser interaction with the same TiN coating
showed that morphology picture is quite different including the reduction of thermal effect.
The article is published in the original. 相似文献
18.
Trace amounts of gold and silver in high-purity iron or steel were preconcentrated by reductive coprecipitation with palladium
using ascorbic acid, and determined by electrothermal atomic absorption spectrometry (ET-AAS). Both gold and silver could
be simultaneously separated and sensitively determined in 10 metals (aluminum, cobalt, chromium, copper, iron, manganese,
molybdenum, nickel, vanadium and zinc). Comparable values were obtained for gold and silver in reference materials (low alloy
steel) by the proposed method and a non-separation method; good agreement was found between the analytical values by both
methods and the certified values. The proposed method is easy, simple and not dependent on sample composition and content.
Moreover, gold and silver in metal samples could be simultaneously separated together with selenium and tellurium. The detection
limits for gold and silver (3 σ) are 0.003 μg g–1 and 0.002 μg g–1, respectively.
Received: 3 February 2000 / Revised: 11 April 2000 / Accepted: 16 April 2000 相似文献
19.
Trace amounts of gold and silver in high-purity iron or steel were preconcentrated by reductive coprecipitation with palladium
using ascorbic acid, and determined by electrothermal atomic absorption spectrometry (ET-AAS). Both gold and silver could
be simultaneously separated and sensitively determined in 10 metals (aluminum, cobalt, chromium, copper, iron, manganese,
molybdenum, nickel, vanadium and zinc). Comparable values were obtained for gold and silver in reference materials (low alloy
steel) by the proposed method and a non-separation method; good agreement was found between the analytical values by both
methods and the certified values. The proposed method is easy, simple and not dependent on sample composition and content.
Moreover, gold and silver in metal samples could be simultaneously separated together with selenium and tellurium. The detection
limits for gold and silver (3 σ) are 0.003 μg g–1 and 0.002 μg g–1, respectively.
Received: 3 February 2000 / Revised: 11 April 2000 / Accepted: 16 April 2000 相似文献
20.
G. Vourlias N. Pistofidis K. Chrissafis G. Stergioudis 《Journal of Thermal Analysis and Calorimetry》2007,90(3):769-775
The oxidation resistance of ferrous materials at elevated temperatures is limited. For that purpose the performance of zinc
coatings deposited with hot-dip galvanizing, pack cementation and thermal spraying was considered. In the present work the
oxidation resistance of these coatings at 400°C was estimated with light microscopy, thermogravimetric analysis and X-ray
diffraction. From this examination it was deduced that in every coating a scale that was mainly composed of ZnO was formed,
while Fe oxides were also detected in galvanized and pack coatings. However, the presence of the Fe/Zn phases inside the galvanized
and pack coatings led to the formation of cracks, which could expose the substrate and thus destabilize the coating. This
phenomenon was not observed in the thermal sprayed coatings, where the Fe/Zn phases were absent. In any case these cracks
are not likely to jeopardize the resistance of the coating because zinc is anodic to steel. Hence, from the above examination
it was deduced that the behavior of zinc coatings would be sufficient at 400°C. 相似文献