In the relentless pursuit of efficient waste management and energy production, the humble high-temperature superheater tube plays a pivotal role. Yet, these critical components often face an early demise due to corrosion, leading to costly downtimes and maintenance headaches for waste incineration plants. A recent study published in ‘Cailiao Baohu’ (translated to ‘Materials Protection’) sheds new light on the corrosion behavior of these tubes, offering hope for extended operational lifespans and improved efficiency.
The research, led by QU Yanmiao from the Henan Boiler and Pressure Vessel Inspection Technology Research Institute, delves into the microscopic world of corrosion, comparing pristine superheater tubes with those that have been in service for a staggering 20,000 hours. The findings paint a vivid picture of the tubes’ battle against high-temperature corrosion, a silent enemy that gnaws away at their integrity.
“Our study revealed that the 12Cr1MoVG high-temperature superheater tubes experienced significant metallic oxidation corrosion on both the inner and outer walls,” QU explains. This corrosion manifests as a dense iron oxide layer on the inner wall, while the outer wall bears the brunt of both metallic oxidation and alkali metal sulfate corrosion, forming a thick, multi-layered scale.
The relentless assault of corrosion takes its toll on the tubes’ microstructure. The inner wall witnesses pearlite spheroidization, a phenomenon where the microstructure changes, leading to a loss of strength. Meanwhile, the outer wall’s pearlite-poor zone narrows, and the core microstructure coarsens slightly. Despite these microstructural changes, the tubes’ tensile strength, elongation, and impact energy remain relatively stable. However, the yield strength takes a significant hit, decreasing by over 60 MPa.
So, what does this mean for the energy sector? The insights gleaned from this study could pave the way for improved corrosion-resistant materials and designs, reducing the frequency of forced shutdowns and maintenance interventions. This, in turn, could lead to increased operational efficiency, reduced downtime, and significant cost savings for waste incineration plants.
Moreover, the study’s findings could influence the development of advanced monitoring techniques, enabling plant operators to predict and prevent corrosion-related failures before they occur. This proactive approach could further enhance the reliability and efficiency of waste incineration boilers, contributing to a more sustainable and efficient energy future.
As the energy sector continues to grapple with the challenges of waste management and energy production, studies like this serve as a beacon of hope, guiding the way towards a more resilient and efficient future. With the insights provided by QU Yanmiao and their team, the industry is one step closer to conquering the corrosion conundrum, ensuring that high-temperature superheater tubes can withstand the test of time and temperature.
