Materials Performance Supplements


Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

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with a VCI additive (0.5% by tank volume) in the biodiesel. In addition to evaluating the conditions experienced in this shipment, the efficacy of the VCI additive was evaluated. It should be noted that only two sensors were available for this test. As such, both sensors were on/in the VCI-treated crawler. Results Laboratory Testing— Modified ASTM D1748 After 185 h of testing, the control part showed significant corrosion, while the part packed with a 50-µm VCI PE liner bag showed no corrosion. When temperature and humidity data were reviewed, it was shown that both tem- perature and humidity increases were signifi- cantly slowed inside the pack with the 50-µm VCI PE over bag. Whereas the internals of the control pack took 16 h to reach external test- ing conditions of 50 °C (Figure 3), the second pack took 36 h to reach 50 °C (Figure 4). When reviewing RH, the control pack reached 75% RH after 62 h of testing, and eventually reached 98%, where it remained for the final 36 h of testing. Conversely, the pack with 50-µm VCI PE over bag reached a high RH of 75% at the end of testing. Real World Analysis— Overseas Shipment 1 Average RH within the shrink-wrapped pallet was 68%, compared to 59% for the PE liner/bag covered pallet. The control pack exceeded 60% RH within four days, com- pared to 31 days for the PE liner/bag + VCI barrier paper system. Near the middle of the shipment, temperature dropped from 25 ⁰C to 9 ⁰C. During this time, the RH within the shrink-wrapped pallet did not change sig- nificantly (Figure 5). Conversely, changes in RH within the second pack closely followed temperature changes during this time, and throughout the rest of the shipment (Figure 6). This suggests that the individual PE bag may be trapping moisture inside. Corrosion was not seen in parts from either packaging system during this evaluation. Real World Analysis— Overseas Shipment 2 The two crawlers were shipped from Iowa, United States on September 2, 2016. They were sailed from port on September 6, 2016, at which point all readings showed daily fluctuations. The internal ( fuel tank) sensor showed these fluctuations until Sep- tember 16, whereas the external sensor con- tinued to show fluctuations until September 21. Both crawlers arrived in Brazil on Sep- tember 29, 2016. Initial inspection took place on October 20, 2016, at which time sensors were sent back to the United States for data collection. The external conditions contin- ued to fluctuate during this time, whereas the internal readings stayed consistent until a few days before initial inspection. Additionally, corrosion was found in the fill neck of the untreated tank upon receipt inspection. In the tank treated with VCI, no corrosion was found. For the purposes of this evaluation, exterior surface corrosion was not monitored. Conclusions Use of temperature and humidity sensors can provide information critical to determin- ing the most effective packaging and preser- vation methods for numerous storage and shipping applications. FIGURE 5 Sensor data from an overseas shipment, United States to China. The data above were the conditions within the control (current) end user system. FIGURE 4 Temperature and RH data from the pack with 50-µm VCI PE liner bag. Temperature reached 50 °C after 36 h, while RH reached a high of 75% at the end of testing. VOLATILE CORROSION INHIBITORS 16 JUNE 2019 MATERIALS PERFORMANCE CORTEC SUPPLEMENT TO MP

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