Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 1 of 18

Corrosion Tests of Fountain Concentrates (FCs) 1. Purpose and Area of Application Preface: Each FC1, independent from the type of press, will be tested according to the same test procedure. The Fogra institute in Munich and the MPA (Staatliche Materialprüfungsanstalt) in Darmstadt are approved by the workshop ”Corrosion on Printing Presses” to perform the required test. Members of this workshop are Heidelberger Druckmaschinen AG, MAN Roland AG and König & Bauer AG. Depending from the type of the press different corrosion limits are applied. The printing presses are classified as follows: - sheetfed offset presses, in the following description termed sheetfed (offset). - web offset presses with continuous feed dampening system (usually heat-set web offset), in the following description termed heatset (offset). - for web offset presses with turbo,- brush,- spray,- or centrifugal dampening system (usually cold-set or semicommercial web offset), in the following description termed coldset (offset). To evaluate the risk on corrosion of metallic components in offset presses caused by FCs the following tests will be performed: 1) Registration of the anodic current density-potential-curve of rolled nickel (German DIN standard No. 2.4060 according to DIN 17740/17750) and the examination of both the maximum current density in case of activity and the break trough potential. 2) Registration of the anodic current density-potential-curve of steel X 20 Cr 13 (Material-No. 1.4021 according German standard DIN EN 10088-3) at polarization in anodic and cathodic directions (pitting plot). 3) Determination of weight loss per unit area of the hardenable steel 100 Cr 6 GKZ at free corrosion as a function of time and calculation of the weight loss per unit area. 4) Determination of the redox potential of the FC. 5) Determination of the anodic current density-potential-curve of platinum (optional) 1.1 Applicable Standards a) b) c) d) 1

DIN 50900 Definitions, part 1 through 3 DIN 50905 Corrosion tests, part 1 through 4 DIN 50918 Electrochemical corrosion tests DIN 50919 Corrosion tests in electrolyte solution by means of contact corrosion

FC = Fountain Solution Concentrate

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 2 of 18

e) DIN 17007 f) DIN 17740 / 17750 g) ASTM-Designation G5-87 ”Standard Reference Test Method for Making Potentiostatic and Potentiodynamic Anodic Polarization Measurements” 2. General Prerequisites for the Ready for Use Fountain Solution Commercial/Film dampening Newspaper/spray dampening

Sheet fed Offset

+ 1800 µS/cm

+ 2000 µS/cm

Max. increase of conductivity in the tap water or test water Max. content of anions in the ready for use fountain sol. acc. to BVD standards as of 1985 [6]

Halogenides 25 ppm Sulphates 50 ppm Nitrates 20 ppm

pH stabilised to

5,0 ± 0,2 trough 9,0 ± 0,2

3. Materials 3.1 Formulation of the fountain solution for test purposes The FC to be tested must be diluted initially before the test in a synthetic water of a total hardness of 10° d (german hardness) which is provid ed by means of dissolving Magnesium sulphate Calcium chloride Calcium nitrate Magnesium acetate Calcium acetate *

MgSO4 · 7 H2O CaCl2 · 2 H2O Ca(NO3)2 · 4 H2O Mg(C2H3O2)2 . 4 H2O Ca(C2H3O2)2 . x H2O

128,3 mg 51,9 mg 38,1 mg 41,5 mg 93,5 mg

*the value of 93,5 mg is valid for a water content of the Calcium acetate of 5,2 %. The formula for the determination of the mass is: n e t w e ig h t C a lc iu m a c e ta t ( m g /l) =

8 8 ,6 4 x 1 0 0 1 0 0 - w a te r c o n te n t (% )

in 1 litre deionized water of max. 3 µS conductivity at 25 °C. The real content of the applied salts should be determined by means of complexometric titrimetric standard substances enabling to adapt the initial weight as requested (this is of special importance for the nonstoichiometric calcium acetate). Thus the applied test water contains 25 ppm chloride, 50 ppm sulphate and 20 ppm nitrate at a total hardness of 10 °d (German hardne ss) showing a mole ratio of 1.5 between calcium and magnesium.

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 3 of 18

The conductivity of the test water will be between 300 µS/cm and 330 µS/cm. The quality of the test water will be determined by means of titrimetric standard substances resulting in a total hardness between 9,8 °d trough 10,2 °d (German hardness). The FC will be applied at the maximum dosage as recommended by the manufacturer in his product manual. 3.2 Test materials 3.2.1 Mild Steel 100 Cr6 GKZ Low alloy cold work steel 100 Cr6 GKZ (annealed for spherical carbides) German DIN standard No. 1.3505 according to DIN 17230 supplier: Böhler. Delivery standard: round bars, Ø 20 mm Preparation of the test coupons for long-term immersion tests: The test coupons, cylindrical steel rods with a diameter of 18,5 mm +/- 0.05 mm and a length of 75 mm (see fig. 1), are grinded on their outer surface down to a maximum roughness Rz of 4 µm. Prior to the test the coupon are prepared as follows -

The surface is wiped with a tissue soaked with distilled acetone The coupons are cleaned two times for 5 min in an ultra sonic bath with acetone (p. A. quality) Dried with warm air. The mass is determined at an accuracy of 0,1 mg. The front surfaces and 10 mm of the cylindrical surface are covered with a protective lacquer for galvanic applications. Alternatively, the front ends of the coupons may be covered by inserting in a sample holder with shaft seals. The dimensions of the test coupons are determined with an accuracy of 0.1 mm.

After the cleaning procedure further handling of the coupons requires to wear cotton or latex gloves. After the preparation the coupons must be stored in a desiccator over silica gel.

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 4 of 18 18,5

protective lacquer Fig. 1: Mild steel coupon for total-immersion tests 3.2.3 Rolled Nickel Material number 2.4060, purity 99.7%, LC-quality, German standard DIN 17740/17750 sheet thickness 2 mm cold rolled, annealed, pickled. Manufacturer Krupp VDM, supplier Hempel, Oberhausen.

3.2.3.2 Preparation of the Test Coupons for Grinding Materials: 2-component epoxy resin, brass disks Ø 18 x 5 mm The nickel electrode disks (Ø 17.5 x 5 mm) are prepared by laser cutting by Lasertechnik All GmbH Westendstr. 123 80339 München The disks are fixed on the brass holders by epoxy resin adhesive. The fin is removed by turning. 3.2.2.3 Equipment for Grinding and Polishing The following description is valid for equipment of the Fogra and must be varied if a varying equipment is used. The preparation procedure of the MPA Darmstadt is given in the appendix. Supplier of the equipment and the consumables: Buehler GmbH In der Steele 2 D-40599 Düsseldorf

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 5 of 18

PHOENIX BETA Automatic grinding and polishing machine Speed stepless varialble VECTOR Pneumatic sample mover Maximum pressure 75 kN at single force application Sample holder for single force application for 18 mm sample diameter (optional equipement) 3.2.2.3 Grinding and Polishing Parameters Grinding: 150 revolutions per minute Single force application with 25 N Sample holder and polisher counterrotating cooling liquid / lubricant H2O Preparation step 1 2 3 4

SiC sandpaper 240 600 1200 2400

grinding time 30 sec 2 min 2.5 min 2.5 min

During the steps 2...4 the coupons must be grinded as long as the grinding traces of the preceding step will be completely disappear. Polishing: Preparation step 5

Polishing time Polishing cloth TEXMET P 2 min (perforated)

6

2 min

TEXMET W

7

2 min

Veltex

Polishing agent Diamond suspension 6 µm (yellow) Diamond suspension 3 µm (green) Diamond suspension 1 µm (blue)

3.2.2.4 Contacting of the Polished Working Electrodes The contact between the nickel electrode and the brass holder is made by the application of an electrical conducting silver lacquer (supplier e.g. Ögussa, Wien, Austria). The contact is checked by measuring the electric resistance (< 1 Ω). 3.2.4 Platinum Pure platinum or platinum/iridium, delivery standard: sheet or mesh

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 6 of 18

The platinum electrodes are glowed in the oxidizing flame of a Bunsen burner before they are used. 3.2.5 Steel X 20 Cr 13 Steel X 20 Cr 13, Material-No. No. 1.4021 according to standard DIN EN 10088-3, 10088 heat treatment condition : QT 800 Delivery standard: round bars, Ø 20 mm Recommended supplier e.g. Thyssen Thyssen-Krupp-Schulte Samples: Cylinders Ø 18 mm x 5mm, grinding with 1200er sand paper Preparation of the coupons prior to use: - grinding with 1200er sand paper straight before use, followed by - rinsing with deionised water - rinsing with 2-propanole propanole - drying in warm air - storing over silica gel 3.3 Laboratory Equipment and Consumables 3.3.1 Permanent Total-immersion immersion Test to Determine the Weight Loss per Unit Area a) Membrane pump or pressurized air supply b) Magnetic stirrer c) Magnetic stirring bars STAR HEAD, HEAD diameter 22 mm,, height 15 mm (see fig. 2)., 2). LABC Labortechnik, Müller & Zillger GbR Postfach 1408 53761 Hennef

Fig. 2: Stirring bar “Star Head”

d) Beakers of 800 ml volume (broad form) according to DIN 12331

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 7 of 18

e) Head for the immersion cup according to fig. 2 made of plastic material (PVC, PETP, Polyolefin)

3

Fig. 3: Head for the immersion cup

6,5

Fig. 4: Fixature for immersion tests

slits 2.5 broad 10 deep

75

20

95

120

40 67 95

f)

Fixature for round coupons and for metal sheets according to fig. 3 made from plastic material e. g. PETP, Polyolefine or Teflon g) Silicon hose with an internal Ø of 4 mm. h) Hypodermic needles with an internal Ø of 0,5 mm. I) Analytical balance with a measurement range of 170 g and an accuracy of 0,1 mg. j) Protective paint for galvanic purposes e. g. yellow cover paint from the company BLASBERG-ETHONE article-No. BN 26.823.4 or Abdecklack gelb Graphische Technik Heimannn Pferdekamp 9 Hamm D-59075 Tel. +49 2381 972160 Fax +49 2381 972162 [email protected], www.heimann-hamm.de

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 8 of 18

3.3.2 Determination of the Anodic Current Density-potential-Curves a) Potentiostatic monitoring system. b) Double-walled beaker of 300 ml volume and a thermostatically monitoring system. c) Electrochemical monitoring cell (see fig. 5 and 6) comprising: - Working electrode A - hydrogen reference electrode B - platinum counter electrode G - Haber-Luggin Capillary HL d) fixature of the working electrode. 4. Corrosion Tests 4.1 Permanent Total-immersion Test do Determine the Weight Loss per Unit Area 4.1.1 Short Description of the Procedure To determine the weight loss per unit area the cylindrical coupons made from hardenable steel 100 Cr6 GKZ will be immersed for 7 days in the fountain solution where the FC is diluted as specified from the manufacturer for application. The immersion bath must be temperature controlled, stirred and saturated with air. Fig. 4 shows a scheme of the immersion test. All measurements must be performed at a constant temperature of 22 ± 1 °C. To determine is - the weight loss per unit area (mg/cm2) in 7 days - the features and characteristics of the corrosion

Fig. 5: Scheme of the permanent total-immersion test

Test parameters

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 9 of 18

Volume of fountain solution

650 ml

Concentration of the FC

according to the manufacturer’s maximum recommendation for water at a total hardness of 10 °d (german hardness)

Test water

deionized water with salt addition so that a total hardness of 10 °d and amounts of 25 ppm chloride, 50 ppm sulphate and 20 ppm nitrate is achieved

Air Flow

150 ml/min

Temperature

22 °C

Coupons

100 Cr6 steel Ø 18.5 mm x 75 mm

number of coupons per test cell

2

test period

7 days

Test Procedure The prepared coupons (degreased, dimensions and mass determined, painted) are inserted into the sample holder (fig. 3). In one beaker are inserted 2 coupons of one type of material. Magnetic stirring bars are given to the beaker , 650 ml of fountain solution is filled in and the beaker closed by the head (fig. 2). The temperature is adjusted at 22 ± 1 °C, the stirring speed is 300 rpm. Than the hose which has a hypodermic needle on its tip is introduced so that the needle is dipping 20 mm into the solution. The air volume is adjusted on 150 ml per minute. The fountain solution is changed every 24 hours during a period of 5 days. Before filling the beaker with new solution the coupons and the fixature are rinsed with deionized water. After 7 days the coupons are cleaned from removable corrosion products by a plastic brush, the protective paint is removed, the samples are rinsed with deionized water, cleaned in warm air and the mass loss ∆m is determined by weighing with an accuracy of ± 0.1 mg. The features and characteristics of corrosion must be stated by inspection of the surface of the test coupon by a stereo microscope. 4.1.3 -

Documentation and Interpretation

Determination of the mass loss per unit area in mg/cm² per 7 days Description of the features and characteristics of corrosion (e.g. pitting corrosion, shallow pitting, general corrosion).

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 10 of 18

After the end of the examinations the coupons must be stored under dry atmosphere. The original test protocols have to be archived. 4.2 Electrochemical Corrosion studies The electrochemical corrosion test of Fcs includes tests on the following materials: - Material number 2.4060, purity 99.7%, LC-quality, German standard DIN 17740/17750 sheet thickness 2 mm cold rolled, annealed, pickled. - Platinum. - Steel X 20 Cr 13, Material-No. 1.4021 according to standard DIN EN 10088-3, heat treatment condition : QT 800 The following data will be determined: - the open circuit potential Ecorr of Ni 2.4060 registrated during a period of 15 min. - The anodic current density-potential-plot of rolled nickel. - The redox potential of the dampening solution. - The anodic current density-potential-plot of platinum in the dampening solution (optional). - The pitting potentials and the repassivability of steel X 20 Cr 13. 4.2.1 Design of the Electrochemical Cell and Realization of the Electrochemical Corrosion test The electrochemical cell consist of a double-walled beaker with a content of 300 ml test solution. The reference and counter electrodes are fixed in a plastic head. The fixature of the working electrode is adjustable so that distance between the working and the reference electrodes can be varied. Working Electrode The metal coupon to study (the working electrode) is fixed in a sample holder made from plastic (e.g. Polyester or Teflon). An effective electrode surface of minimum 1 cm² is excluded by a Teflon- or Viton-O-washer. Reference Electrode The potential reference is a commercial reference electrode (e.g, Ag/AgCl) which is inserted to an electrolyte key filled with a 3 mol/l KCl solution. This electrolyte key is inserted to the Haber-Luggin-Capillary with a diaphragm filled with the test solution. The distance between the tip of the Haber-Luggin-Capillary and the working electrode must be 20 mm. Counter Electrode The counter electrode is a platinum sheet or a platinum mesh. The fountain solution is neither stirred nor aerated. The temperature is 40 ± 1 °C.

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 11 of 18

The electrochemical cell has the three-electrode-scheme which is ordinary used for electrochemical D.C. measurements.

Fig. 6: schematic cell design for electrochemical corrosion studies

A possible practical realisation of the scheme in Fig. 6 is shown in Fig. 7:

Fig. 7: Measuring cell for electrochemical corrosion studies

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 12 of 18

Test Parameters Volume of fountain solution

300 ml

Temperature

40 °C

fountain solution

not stirred and not aerated

Working electrode Area of the working electrode Counter electrode Reference electrode Haber-Lugin-Capillary Distance between the working electrode and the Haber-Lugin-Capillary Registration of the open circuit potential Current density-potential-curve Starting potential Final potential Polarisation rate Results (see Fig. 9) Reference potential

Rolled nickel polished for metallography with a diamond paste of 1µm in the last polishing step 1 cm² ± 0.01 cm² Platinum sheet or platinum mesh e.g. Ag/AgCl with a salt bridge filled with 3 mol/l KCl Filled with fountain solution, with ceramic diaphragm 20 mm ± 0.2 mm For a period of 15 min Free corrosion potential – 10 mV Break through potential or 1200 mVSHE, resp. 1000 mV per hour • •

curve a) : passed curve b) : failed

Standard Hydrogen Electrode (SHE)

4.2.2 Calibration of the Test Equipment for Electrochemical Corrosion Studies -

The actual potential of the reference electrode used in the test is determined in comparison to a standard reference (e.g. calomel) electrode. The anodic current density-potential-curve of rolled nickel 2.4060 in a 0.05 molar (0.1-normal) sulphuric acid must be measured and compared with the reference curve (fig.7).

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 13 of 18

-2

lg I (A/cm²)

-3

-4

-5

-6

-7 0

200

400

600

800

1000

1200

E(mV vs. SHE)

Fig. 8: current density-potential-curve of rolled nickel 2.4060 in 0.05 molar sulphuric acid. 4.2.3 Description of the nickel resistance test a) The electrochemical cell is filled with 300 ml fountain solution, the temperature adjusted at 40 ± 1 °C and cell fitted. b) Determination of the open circuit potential of the working electrode during a period of 15 min. c) Determination of the anodic current-potential-curve in the potential range from (Ecorr – 10 mV) to the break through potential or to 1200 mVSHE, respectively. d) After the test the surface of the working electrode has to be inspected on marks of corrosion. 1000 a: passed b: not acceptable 100

limit 10 µA/cm²

10

1

0.1 -100

100

300

500

700

900

1100

potential (mV vs. SHE)

Fig. 9: current density-potential-curve of rolled nickel 2.4060 in fountain solutions

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 14 of 18

Regarding curve a: The critical passivation current density is smaller than 10 µA/cm². The breakthrough potential is higher than 700 mVSHE. The corresponding fountain solution concentrate passes the nickel resistance test. Regarding curve b: The critical passivation current density exceeds the value of 10 µA/cm². The corresponding fountain solution concentrate fails the nickel resistance test. 4.2.4 Electrochemical Examination (Pitting plot) of the risk of local corrosion of alloid steel An electrochemical pitting plot on steel X 20 Cr 13, material-No. 1.4021 according German standard DIN 17007 has to be performed (see fig. 9). Parameters of the electrochemical pitting plot Volume of the fountain solution temperature fountain solution working electrode area of the working electrode counter electrode Reference electrode Filling of the Haber-Luggin-capillary distance between the diaphragm of the reference electrode and the working electrode Current-potential-plot starting potential

300 ml 40 °C ± 1 K Not stirred and not aerated - steel X 20 Cr 13, freshly grinded with 1200er SiC-paper 1 cm² ± 0,01 cm² Platinum sheet or platinum mesh e.g. Ag/AgCl, filling of the salt bridge: 3 m KCl-Lösung Fountain solution 20 mm ± 0,2 mm

open-circuit potential – 10 mV •

final potential

Polarisation rate breakthrough potential (I > 10 µA/cm²) Threshhold current (Ithreshold)

if i < 50 µA/cm²; E=+1200 mVSHE • if i > 50 µA/cm²; the reversal test is performed until the intersection with the plot at polarization in anodic direction 1000 mV/h If E > Eredox + 250 mV 50 µA/cm²

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 15 of 18

Result (fig. 10)

• • •

Reference potential

Standard hydrogen electrode (SHE)

curve a: passed curve b: passed curve c: failed

material X20Cr13 electrolytic solutions at 40 °C; satured with air 1 a) O.K. b) acceptable c) inacceptable 0.1 c)

b) a)

0.01

0.001

0.0001

- 200

0

200

potential in mV vs. SHE

400

600 800 1000 redox potential limit potential ( = redox potential + 250 mV)

1200 1200

fig. 10: schematic diagram of the pitting plot of steel X20Cr13 with and without formation of pits. Regarding curve a): The current potential plot does not show a pitting potential. The current density at polarisation in anodic direction is smaller than 50 µA/cm². The test is finished at a final potential of 1200 mVSHE. The corresponding fountain solution concentrate passes the X 20 Cr 13 resistance test. Regarding curve b): The formation of pits is starting at a potential which is higher than the sum of the redox potential + 250 mV; after reversing of the direction of polarisation to cathodic direction the material is repassivated at a potential value which is higher than the sum of the redox potential + 250 mV (intersection of the cathodic and the anodic branch of the curve). The corresponding fountain solution concentrate passes the X 20 Cr 13 resistance test.

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 16 of 18

Regarding curve c): The formation of pits is starting at a potential which is smaller than the sum of the redox potential + 250 mV; after reversing of the direction of polarisation to cathodic direction the material is not repassivated. The corresponding fountain solution concentrate fails the X 20 Cr 13 resistance test. In all cases the critical passivation current density must not be higher than 10 µA/cm². 4.2.5 Test on Redox Systems and Easily Oxidisable Components In the case that a fountain concentrate has exceeded the maximum current density limit of 20 µA/cm² and so has not passed the test it must be checked if the reason of the current density-potential-curve is the occurence of a redox systems or an easily oxidizable component in the fountain solution. The following tests must be done: a) Measurement of the redox potential of the solution by switching the platinum counter electrode as the working electrode. b) Registration of the open circuit c) potential of platinum during a period of 15 min. d) Determination of the anodic current density-potential-curve of platinum from a starting potential of Ecorr – 10 mV to the break through potential or to a potential of 1200 mVSHE , resp. Before the measurements acc. to pt. b) and c) the manufacturer of the fountain concentrate must agree to this optional test. 4.2.6 Results and Documentation The following results are given in the report: a) Nickel 200 - Open circuit potential Ecorr - The critical passivation current density - The breakthrough potential. b) Steel X 20 Cr 13 - Open circuit potential Ecorr - Break through potential relative to a current density of 10 µA/cm². - Break through potential relative to a current density of 50 µA/cm² in the case that this current density is exceeded at a potential smaller than 1200 mVSHE. - Passivation current density and the passivation potential - The potential of repassivation c) The redox potential. d) Anodic current density-potential-curve of platinum (optional)

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 17 of 18

5

Limiting Values for the Approval of Fountain Concentrates

5.1

Electrochemical Test of Rolled Nickel (Nickel 200 with a Purity of 99.6 %, German Material No. 2.4060)

Maximum current density imax in the range from Ecorr to 700 mVSHE imax ≤ 10 µA/cm² 10 µA/cm² < imax

Heatset/Film dampening

Newspaper/ spray dampening

Sheet fed Offset

The fountain solution concentrate passes the nickel resistance test The fount does not pass the nickel resistance test

The tolerance of the current density values is ± 10 %. 5.2

Electrochemical Test of Steel X 20 Cr 13 (German Material No. 1.4021)

The fountain solution concentrate passes the test, if -

-

-

A current density of 10 µA/cm² is not exceeded until a potential value of ERedox + 250 mV. the current-density plot does not show a pitting potential at a potential value of less than 1200 mVH [fig. 10, graph a]. the current-potential plot shows a pitting potential at a potential value of less than +1200 mVH and the values of the pitting potential and the potential of repassivation are larger than the redox potential + 250 mV [fig. 10, graph b].

The fountain solution concentrate fails the test, if -

-

A current density of 10 µA/cm² is exceeded until a potential value of ERedox. + 250 mV. The current-potential plot shows a pitting potential at a potential value of less than +1200 mVH and the potential of the repassivation is smaller than the redox potential + 250 mV [fig. 10, graph c].

see also point 4.2.4

Testing Scheme for the Corrosion Test of Fountain Concentrates, Version 09/2016, page 18 of 18

5.3

Total-immersion Test of steel 100 Cr 6 GKZ

Mass loss rate ∆m [mg(cm2 ∗7 d)]

Heatset / Film dampening

Steel 100 Cr 6 GKZ 20 mg/(cm2 ·7d) (VdEh 1.3505) Shallow corrosion 7 1) 2) 3) 4) 5) 6) 7) 8) 9)

Newspaper / spray dampening 15 mg/(cm2 ·7d)

not tolerated

Sheet fed Offset 25 mg/(cm2 ·7d) tolerated

Literature DIN 50 900 Begriffe, Teil 1 bis 3 DIN 50 905 Korrosionsuntersuchungen, Teil 1 bis 4 DIN 50 918 Elektrochemische Korrosionsuntersuchungen DIN 50 919 Korrosionsuntersuchungen der Kontaktkorrosion in Elektrolytlösungen E. Heitz, R. Henkhaus, A. Rahmel, ”Korrosionskunde im Experiment”, 2. Aufl. VCHVerlag, Weinheim 1990 BVD 1985, Bundesverband Druck e.V. , Empfehlungen für den Korrosionsschutz bei Offsetdruckmaschinen, Wiesbaden 1985 M. Gugau, H. Speckhardt: Elektrochemische Untersuchungen zur Korrosion von Nickelüberzügen. Werkstoffe und Korrosion 42 (1991) 296-308 M. Gugau, F. W. Hirth, H. Speckhardt: Korrosionsschutz bei Offsetdruckmaschinen. Metalloberfläche 39 (1985) 171-175 H. Spähn, K. Fäßler: Kontaktkorrosion im Maschinen- und Apparatebau. Der Maschinenschaden 40 (1967), Heft 3, Seite 81-89

IMPRESSUM:

Fogra Forschungsgesellschaft Druck e.V. Vorstandsvorsitzender Stefan Aumüller Redaktion: Dipl.-Chem. Stephan Dietzel Anschrift: -Institut, Streitfeldstr. 19, 81673 München Telefon: +49 89 43182 352 Telefon: +49 89 43182 100 E-mail: [email protected] Internet: www.Fogra.org © 2015 by Fogra