AMP_04_May_June_2021_Digital_Edition

A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A Y / J U N E 2 0 2 1 3 0 One of the issues with these sce- narios is the lack of data about the specific conditions of a surface or con- centration of a contaminant in a sys- tem. The new and dynamic situation demands characterization and under- standing, which is difficult because the situation may evolve and change. In the COVID-19 pandemic especially, physical access to hardware and normal collabo- ration with colleagues to collect inspec- tion data have been difficult because of the necessary social distancing and dis- infection procedures in place. Sometimes sufficient data can be collected to mitigate the risk as the sce- nario progresses in time. For example, a system that is shut down for 90 days can potentially be monitored for changing condition over time. A 30-day monitor- ing window may be sufficient to collect enough information tomanage the pos- tulated degradation mechanism. These inspections may be in the form of non- destructive evaluation (NDE) like ultra- sonic or eddy current or may be visual only (Fig. 3). Sometimes the investiga- tion may require a borescope for a tight location or disassembly to access hid- den or restricted areas. PRESERVATION One avenue of protection is the methodical application of preservation techniques to mitigate the effects of an unexpected shutdown condition. An engineer should always understand the potential for a short shutdown to be ex- tended or permanent, and procedures should already be in place to ensure that future operability and safety are maintained. Even parts and systems deemed inoperable or insufficient may have use to support future operations. Chief among these practices is in- dustrial hygiene, including adherence to cleanliness and monitoring proce- dures. Equipment and rinse baths must be maintained according to refresh and reconstitution schedules and moni- tored appropriately for deviation from standards. Unexpected contamination or particle buildup in typical process- es may go unnoticed or be ignored as mundane job aspects. As the level of potential severity of exposure to vari- ous contaminant species depends on the material or alloy genre in question, even common exposure to table salt from a worker’s food may present a vi- able degradation contributor. Flushing of systems at a consis- tent or increased rate may support mitigation of potential issues. With oil, lubrication, and fuel, changing out in- teracting media may reduce the poten- tial for various forms of degradation. Additionally, using desiccant or remov- ing stagnant water may be of benefit to the overall system. The type of preser- vation technique is always based on the system being evaluated and the chemi- cal compatibility of its constituents. THE PATH FOR SURVIVORSHIP The way to understand and over- come these challenges is through inte- gration of various materials disciplines. From failure analysis to material char- acterization, process chemistry, and material applications, all areas have a vital part in shaping the response to these scenarios. Even beyond the ma- terials realm, coordination with other engineering departments such as struc- tural, quality, manufacturing, and re- pair are all vital to ensure that product is maintained and assessed properly for its long-term use. The preparation and consider- ation for shutdowns and accidents out- side of design basis should always be within the realm of feasible introspec- tion by engineers. Although more than a year has passed since the beginning of lockdown and the onset of the COVID-19 pandemic, other scenarios and chal- lenges will surely occur in the future. It is the responsibility of engineers to prepare and adopt a proactive—rather than reactive—attitude to understand these conditions and to adapt appropri- ately to preserve public health and safe- ty. Merely surviving these troubles, and arriving on the other side, should not be the goal. We must continue to strive to adapt and to protect, to become a pos- itive force to help our customers, col- leagues, friends, and family. ~AM&P Lead image: 2019-nCoV spike protein, courtesy of Jason McLellan/University of Texas at Austin. Note: Opinions expressed are from the author only and are not reflective of the opinions or positions of current or former employers. Specific evaluation of safety-related hardware or systems must be made on a case-by-case basis per appropriate warranties, design doc- umentation, and regulations. For more information: Dan Denis, PE, senior consultant in metallurgy and materials, Structural Integrity Associa- tes Inc., Simsbury, CT, 570.561.5097, ddenis@structint.com . Fig. 3 — Ultrasonic or other NDE techniques may provide additional data to understand atypical operating or standby situations. STEPS TO EVALUATE 1. Has expected operation changed for the component? 2. How do these functional chang- es manifest for the component (e.g., longer stagnation period, reduced equipment flushing, etc.)? 3. Do these manifestations affect original design considerations? 4. Can risk be mitigated through observation, inspection, or testing? 5. Can the change in operation be brought within the original design considerations? 6. Do design considerations re- quire modification or reanalysis?