Preet SinghAssociate Professor School of Materials Science and Engineering Ph.D., University of Newcastle Upon Tyne,    England, 1988

Preet M. Singh obtained his M.Tech. in Corrosion Science and Technology from the Indian Institute of Technology, Bombay, in 1985 and his Ph.D. in Materials Engineering from the University of Newcastle Upon Tyne, England, in 1988. He received Alcan International's Fellowship in 1988-90 to work on "Effects of Low Melting Point Impurities on Slow Crack Growth in Al Alloys." From 1990 to 1996, he joined as a Senior Research Associate at Case Western Reserve University, Cleveland, Ohio, working on various material and corrosion related research projects, including Damage Accumulation in Metal Matrix Composites (MMCs), Environmental Sensitive Fracture of Al-alloys MMCs, and High Temperature Oxidation of Nb/Nb₅Si₃ Composites.

His research interests include Corrosion, Stress Corrosion Cracking, Corrosion Fatigue, Microstructure/Property Relationships in Alloys and Composite Materials.

Research Summary

Reliable performance of the materials used to fabricate the plant equipment is extremely important for the manufacture of a high quality product. Material selection is generally based on the required material properties, low initial capital investment, and minimum maintenance. Changing process parameters to improve the pulping and papermaking processes often lead to higher corrosion susceptibilities of the used materials. Moreover, with increase in capital cost, there is pressure to extend the life of existing plants beyond their original design life. Corrosion and Materials Engineers are playing a key role in selecting, maintaining, and modifying materials for the industry's changing needs. Corrosion and Materials research includes testing of candidate alloys in the laboratory to understand the mechanisms of material degradation and to develop a mitigation strategy. Further field studies are done by exposing test coupons directly to specific environments in the pulp and paper mills.

Main areas of concern to the pulp and paper industry can be divided into two categories: aqueous corrosion and high temperature corrosion. Most of the aqueous problems are a result of the highly corrosive liquor streams found in the pulp mill. Corrosion in white, green, and black liquor tanks and digesters needs a better understanding for mitigation of corrosion-related problems. With mill closure, the concentrations of various dissolved nonprocess elements are expected to increase in various areas of pulping and papermaking processes. Research at IPST in this field is aimed at understanding the environmental changes in closed mills and their effect on the corrosion and materials performance of the existing equipment as well as on new materials.

One of the major research activities is related to the corrosion problems in the kraft recovery boilers. Recovery boilers are used to recover pulping chemicals and to raise steam by burning the organic residues present in spent pulping liquors. There are a range of problems associated with recovery boilers, e.g., high temperature corrosion (oxidation or sulfidation), molten salt corrosion, and aqueous corrosion due to condensed liquids in the cooler regions of the boiler. Research is being carried out in all of the above-mentioned fields at IPST. Composite tube cracking in the kraft recovery boilers is one of the major unsolved problems in the industry. Collaborative research at IPST in the field of stress corrosion cracking in washwater is directed toward a better understanding and mitigation of this problem.