NAVAL STEELS: FROM LABORATORY TO APPLICATION (21/09/21)
Speaker and Affliation:
Dr. R. Balamuralikrishnan
Defence Metallurgical Research Laboratory (DMRL)
Hyderabad
When?
21th September, 2021 (Thursday), 04:00 PM (India Standard Time)
Location
Abstract
High performance steels deliver excellent performance for rather critical applications that have stringent, often conflicting, property requirements. Steels for naval structural applications are subject to one of the harshest operating environments, with constant exposure to sea water, various types of static and dynamic loading, and large variation in temperatures. These steels are required to possess necessary ambient temperature strength (minimum yield strength: 390 to 800MPa for different variants) and excellent low temperature impact toughness (~ 80J minimum, at minus 40o C or even minus 60o C). Apart from these, they are also expected to have good weldability and adequate corrosion resistance. For over two decades, DMRL has been actively working in the development/indigenization of low alloy steels for naval applications with yield strengths of about 400MPa to about 800MPa, which are required to have impact toughness in excess of 80J at -40o C. Our efforts have spanned the entire spectrum from lab scale scientific studies to industrial scale production and certification for final use. Given the application, large sheets/plates, in widths ranging from 1.5 to 3m, and in lengths well in excess of 6m, constitute the bulk of the requirement. Thus, while studies at lab scale involve melts of 30-50kg, industrial production involves melts of 50 tonnes or more! The talk will provide a few examples from our work spanning the entire range from the developmental phase to the industrial production phase. Special emphasis will be given to illustrating how (lab-scale) R&D was employed to address challenges that arose during bulk production in order to improve product reliability and consistency