Cryogenic treatment can extend lifespan of stainless steel: Punjabi University research

Ravneet Singh

Patiala, October 10

A Punjabi University research scholar has found that cryogenic treatment of stainless steel can extend the lifespan of the metal used in turbines of hydropower plants across the world, cut costs, and help produce more energy.

The research was completed by scholar Munish Kumar as part of his PhD under the guidance of Hazoor Singh Sidhu, Professor, Department of Mechanical Engineering, Yadavindra College of Engineering of Punjabi University, Patiala, and Professor Buta Singh, Vice-Chancellor, Maharaja Ranjit Singh Punjab Technical University, Bathinda.

Munish said stainless steel was widely used in hydropower plants for manufacturing of various components. It gets eroded due to its poor tribological characteristics.

“This happens especially during the rainy season when the quantity of sand particles increases in the water stream. Sand particles continuously fall onto the stainless steel blades of the turbines and lead to their erosion. The turbines then need to be stopped and the blades removed. It affects the functioning of hydropower plants across the world as it wastes precious time in changing the blades and increases costs,” he said.

His guide Prof Hazoor Singh said their research had found that cryogenic treatment (treating the metal to temperatures below -190 °C (-310°F)) done on stainless steel refines its internal structure. “This then improves the metal’s resistance to erosion, which ultimately improves its life by 15 to 20 per cent,” he said.

The research scholar also prepared a slurry erosion testing rig as per the ASTM standards as part of the research study and found that the treatment helped reduce erosion of stainless steel. Prof Buta Singh said this was a simple solution to reduce the erosion in metals, which would lead to an increase in the power generation capacity of hydropower plants by reducing its shutting time.