APPENDIX A LPR STANDARD OPERATING PROCEDURE

Transcription

1 APPENDIX A LPR STANDARD OPERATING PROCEDURE

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3 LPR Corrosion Study Standard Operation Procedure Alloys: AA356.2, A36, AA6061-T6, CDA 360, AZ91C-T6 Project: NCHRP, June 14, Pre-Test Preparation: 1.1 Glass cleaning: -Acid-clean glass beakers and graduated cylinder with 1:1 HCl -Rinse all surfaces very well -Dump waste acid in waste acid vessel for disposal -If solution becomes quite coloured, then repeat -Rinse flasks well with tap water -Rinse with reverse osmosis de-ionized water >4 times -Inspect glassware 1.2 Electrode holder cleaning: -Wash electrode holder under tap with soap and water, rubbing gently with cloth -Rinse well with tap water and then alcohol -Visually inspect for cleanliness 1.3 Electrode cleaning: -Sandpaper clean electrodes on drill press (wet for magnesium sample) -Use separate sandpaper (600 grit) for each sample, avoid cross-contamination of metals -Thread 32tpi holder shaft into sample then put other end of threaded shaft into drill press -At high speed gently pinch paper between thumb and fingers around sample and slide up and down exposing all fresh metal and evenly abrading sample, press paper flat onto end of electrode -Stop when all previous corrosion product is removed -Repeat pinching of sample with paper towel while spinning sample to remove any other debris -Rinse off with alcohol and gloved finger rub, flush threaded hole, then blow-dry -Maintain cleanliness of samples at all times by avoiding touching them with bare hands to avoid depositing oil, or contacting them with dirty surfaces -Store in closed clean petri dish -Weigh samples when dry and measure dimensions

4 2.0 Performance of LPR Test: 2.1 Sample cell assembly: -Measure solution into graduated cylinder to nearest ml. -Initially rinse graduated cylinder with a very small amount (~15 ml) of test solution and discard -Shake flask as dry as possible -1% and 10% tests require a 750 ml solution; full strength solutions require 500 ml -Pour solution into test beaker; CDA 360 full strength requires waisted beaker to increase solution height -Put clean rubber washer on electrode holder and screw electrode on firmly so to form a seal -Order electrodes in sample cell, left to right: electrode 1 on holder A, 2 on B, and 3 on C, or as necessary and record -For 15 minute reading times of 1% and 10% solutions immerse assembled tops into solution at 16 minute intervals, noting initial immersion time. For 3 minute reading of 100% solution, immerse 4 minutes apart -Plug leads hanging from the test stand into the probe holders, A on left, B centre, C right 2.2 Data acquisition: -Prepare data sheets from template, update solution, date, and test number -After assembly and immersion of final cell, take potential reading of first cell Instrument -Plug and screw lead from MS1500L into test stand plug above sample -Turn MS1500L on (slide switch on bottom left to the right) -Push ENTER key to enter the electrode selection menu -Push arrow keys to move to required electrode (specifies alloy, corrosion/potential, duration) -Push ENTER to select -Push arrow key to select MAKE MEASUREMENT -Verify info in window is correct -Push ENTER again to start -Almost instantly a POT value will appear in window, push ENTER to save and record on worksheet -Note temperature and observations -Repeat for each cell, 16 minutes apart and after 72-hour corrosion reading (4 minutes and 24 hours for 100%)

5 -Take corrosion measurements 3, 6, 24, 48, and 72 hours after initial immersion (1, 3, 6, 24 hours for 100%) Instrument -Turn on -Push ENTER key to enter the electrode selection menu -Push arrow keys to move to required electrode -Push ENTER to select -Push arrow key to select MAKE MEASUREMENT -Verify info in window is correct -Push ENTER again to start -After 15 minutes, a MPY value appears in window, push ENTER to save, record value on worksheet -Repeat measurement process on each cell, 16 minutes apart -Take potential reading for each cell after 72-hour corrosion reading (24 hours for 100%) 3.0 Completion of Test: -Take photos of any unusual phenomena -Remove samples from solution, confirm ordering of electrodes -Individually ultrasonic clean each alloy sample in a beaker of Alconox solution (~1 hr) -Rub samples with paper towel, rinse with alcohol, flush tapped hole, blow dry, and weigh -If necessary, submit for visual examination -Upload data from MS1500L data logger to PC -Complete hand-notated table filled during test, transfer to digital Excel copy and save to folder for that test

6 Figure A-1 General View of LPR Test Arrangement with Meter Affixed to Brass (CDA 360) Samples

7 APPENDIX B CORROSION TEST WORKSHEET AND SUMMARY

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9 Table B-1 NCHRP Corrosion Test Worksheet and Summary NCHRP Corrosion Test Work Sheet and Summary Solution: # Test # Concentration: % Soln Volume: ml Start Date: End Date: 3-Jan-00 Test UNS Probe ID Mass after Immersion 1.0 hr 3 hr 6 hr 24 hr 48 hr 72 hr 72 hr Mass after Mass Coupon Probe Probe Approx. Metal MPY coupon No. corr. pot. cleaning, time potential corr corr corr corr corr potential test and US change order Length Dia. Probe Area Density alloy pretest (g) (mv) (mpy) (mpy) (mpy) (mpy) (mpy) (mv) cleaning (g) (g) (in) (in) (in2) g/cc Temp Date AA A :00 1:04 3:00 6:00 0:00 0:00 0:00 0: A B C Project: A36 K :16 1:20 3:16 6:16 0:16 0:16 0:16 0: A B C AA 6061-T6 A :32 1:36 3:32 6:32 0:32 0:32 0:32 0: A B C CDA 360 C :48 1:52 3:48 6:48 0:48 0:48 0:48 1: A B C Mg AZ91C M :04 2:08 4:04 7:04 1:04 1:04 1:04 1: A B C Observations: A = Reference B = Test C = Auxiliary 0 Hr 1 Hr 6 Hr 24 Hr 48 Hr 72 Hr Page B-1

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11 APPENDIX C CORROSION RATE DATA SUMMARIES

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13 Table C-1 Corrosion Rate Data Summary for AA356.2 Cast Aluminum Alloy Corrosion Rate Data Summary - A356.2, Cast Aluminum Alloy Corr MPY Soln Conc Time NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA % Hr OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride AVE MAX MIN STDEV RSD 40% 3% 2% 63% 49% 33% 14% 2% 8% 11% 39% 119% 20% 13% 6% AVE MAX MIN STDEV RSD 14% 31% 18% 108% 47% 5% 42% 12% 59% 50% 30% 6% 63% 3% 16% AVE MAX MIN STDEV RSD 122% 51% 52% 159% 163% 81% 146% 79% 114% 170% 101% 71% 148% 105% 82% Page C-1

14 Table C-2 Corrosion Rate Data Summary for A36 Structural Steel Corrosion Rate Data Summary - A36, Structural Steel Corr MPY Soln Conc Time NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA % Hr OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride AVE MAX MIN STDEV RSD 200% 25% 25% 56% 20% 63% 37% 65% 69% 35% 27% 69% 96% 178% 0% AVE MAX MIN STDEV RSD 18% 39% 49% 58% 61% 86% 37% 53% 35% 38% 81% 17% 91% 219% 137% AVE MAX MIN STDEV RSD 65% 102% 15% 53% 8% 28% 9% 28% 47% 196% 158% 30% 83% 35% 46% Page C-2

15 Table C-3 Corrosion Rate Data Summary for AA6061-T6 Wrought Aluminum Alloy Corrosion Rate Data Summary - AA6061-T6, Wrought Aluminum Alloy Corr MPY Soln Conc Time NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA % Hr OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride AVE MAX MIN STDEV RSD 26% 3% 7% 5% 86% 3% 13% 11% 14% 10% 20% 5% 10% 25% 23% AVE MAX MIN STDEV RSD 30% 63% 12% 2% 70% 9% 16% 7% 23% 21% 51% 3% 68% 3% 7% AVE MAX MIN STDEV RSD 115% 71% 133% 131% 120% 100% 74% 163% 112% 124% 68% 130% 91% 105% 87% Page C-3

16 Table C-4 Corrosion Rate Data Summary for CDA 360 Free Machining Brass Corrosion Rate Data Summary - CDA36000, Free Machining Brass Corr MPY Soln Conc Time NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA % Hr OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride AVE MAX MIN STDEV RSD 67% 97% 2% 21% 53% 115% 72% 45% 70% 82% 88% 79% 77% 8% 45% AVE MAX MIN STDEV RSD 23% 98% 33% 13% 26% 134% 61% 98% 41% 86% 23% 21% 31% 11% 45% AVE MAX MIN STDEV RSD 145% 119% 258% 10% 127% 179% 31% 48% 75% 75% 51% 35% 22% 147% 172% Page C-4

17 Table C-5 Corrosion Rate Data Summary for AZ91C-T6 Magnesium Alloy Corrosion Rate Data Summary - Alloy AZ91C, Magnesium Alloy Corr MPY Soln Conc Time NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA % Hr OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride OVER OVER OVER OVER OVER OVER OVER OVER OVER OVER OVER OVER OVER OVER OVER AVE na MAX MIN STDEV na na RSD 74% 42% 73% 56% 68% na 46% na 104% 38% 56% 15% 66% 20% 38% OVER OVER OVER OVER OVER AVE MAX MIN STDEV RSD 48% 58% 23% 83% 58% 32% 27% 26% 38% 17% 80% 71% 65% 43% 75% AVE MAX MIN STDEV RSD 91% 22% 72% 41% 31% 35% 36% 80% 63% 57% 63% 96% 76% 9% 46% Page C-5

18 Table C-6 Estimate of Corrosion Rates by Area under Corrosion Rate vs. Time Curve (Integration) for AA356.2 Cast Aluminum Alloy Estimate of Corrosion Rates by Area Under Corrosion Rate vs. Time Curve (Integration) A356.2, Cast Aluminum Alloy Trapezoidal Area Average NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride % Total Area Total Area/ % Total Area Total Area/ % Total Area Total Area/ Page C-6

19 Table C-7 Estimate of Corrosion Rates by Area under Corrosion Rate vs. Time Curve (Integration) for A36 Structural Steel Estimate of Corrosion Rates by Area Under Corrosion Rate vs. Time Curve (Integration) A36, Structural Steel Trapezoidal Area Average NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride % Total Area Total Area/ % Total Area Total Area/ % Total Area Total Area/ Page C-7

20 Table C-8 Estimate of Corrosion Rates by Area under Corrosion Rate vs. Time Curve (Integration) for AA6061-T6 Wrought Aluminum Alloy Estimate of Corrosion Rates by Area Under Corrosion Rate vs. Time Curve (Integration) AA6061, Wrought Aluminum Alloy Trapezoidal Area Average NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride % Total Area Total Area/ % Total Area Total Area/ Total Area Total Area/ Page C-8

21 Table C-9 Estimate of Corrosion Rates by Area under Corrosion Rate vs. Time Curve (Integration) for CDA 360 Free Machining Brass Estimate of Corrosion Rates by Area Under Corrosion Rate vs. Time Curve (Integration) CDA36000, Free Machining Brass Trapezoidal Area Average NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride % Total Area Total Area/ % Total Area Total Area/ % Total Area Total Area/ Page C-9

22 Table C-10 Estimate of Corrosion Rates by Area under Corrosion Rate vs. Time Curve (Integration) for AZ91C-T6 Magnesium Alloy Estimate of Corrosion Rates by Area Under Corrosion Rate vs. Time Curve (Integration) AZ91C, Magnesium Alloy Trapezoidal Area Average NaCl + NaCl + NaCl NaCl + CaCl 2 CaCl 2 + CaCl 2 + CaCl 2 + MgCl 2 MgCl 2 + MgCl 2 + Blended CMA CMAK KA OMB OMB P OMB C, A OMB OMB, TEA OMB Chloride % Total Area > Total Area/24 > % Total Area > Total Area/72 > % Total Area > Total Area/72 > * note: values >200mpy are set to 200mpy minimum for the area calculation Page C-10

23 APPENDIX D COMPARISON OF CORROSION RATES BY LPR VS. WEIGHT LOSS

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25 Table D-1 AA356.2 Cast Aluminum Alloy AA356.2 Corrosion Rate Weight Loss Conc Sol'n LPR WL MPY 100% % % % % % % % % % % % % % % % % n/a Not Available 10% % % % % % % % % % % % % % % % % % % % % % % % % % % % Page D-1

26 Table D-2 A36 Structural Steel A36 Corrosion Rate Conc Sol'n LPR WL MPY 100% % % % % % % % % % % % % % % % % n/a Not Available 10% % % % % % % % % % % % % % % % % % % % % % % % % % % % Page D-2

27 Table D-3 AA6061-T6 Wrought Aluminum Alloy AA6061 Corrosion Rate Conc Sol'n LPR WL MPY 100% % % % % % % % % % % % % % % % % n/a Not Available 10% % % % % % % % % % % % % % % % % % % % % % % % % % % % Page D-3

28 Table D-4 CDA 360 Free Machining Brass CDA360 Corrosion Rate Conc Sol'n LPR WL 100% % % % % % % % % % % % % % % % % n/a Not Available 10% % % % % % % % % % % % % % % % % % % % % % % % % % % % Page D-4

29 Table D-5 AZ91C-T6 Magnesium Alloy AZ91C Corrosion Rate Conc Sol'n LPR WL MPY 100% % % % % % 17 #DIV/ % % % % % % % % % % % n/a Not Available 10% % % % % % % % % % % % % % % % % % % % % % % % % % % % Page D-5

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