Talk given by Prof. K. Bhanu Sankara Rao Mahatma Gandhi Institute of Technology Gandipet, Hyderabad India Abstract: The development of high performance Nano-Oxide Dispersion Strengthened alloys is essential for the successful operation of the fuel clad tubes in fast reactors, first wall and blanket systems in fusion reactors and ultra supercritical power plant steam turbines. Compared with austenitic stainless steels, ferritic steels are known to present superior radiation resistance but inferior strength at high temperatures. The strength disadvantage can be surmountable by inserting nano-size oxide dispersoids in the ferrite/ferrite-martensite matrix, to form what is known as ODS alloy. Processing plays a major role in the performance of these alloys. Producing these alloys in large size is a very difficult. task. Steel processing techniques for manufacturing of base metal powders are not perfected. Production of the products from nano-oxide dispersion strengthened alloys involves lot of metal forming techniques such as rolling and extrusion promoting elongated grain structures that cause anisotropic behavior which can have detrimental effects such as reduced mechanical properties in along certain directions in the material. Furthermore, characterization of their microstructures is a cumbersome process. There are several steps involved in the development of ODS alloy tubes and plates for aforementioned applications. These include the production of powders of high purity matrix material and dispersoids, control of interstitial pick up during attritor milling, production of cans for extrusion, optimization of extrusion temperature and reduction ratio in the production of ingots, manufacturing of hollow tubes, reduction of tube wall thickness by pilgering, establishing intermediate annealing schedules, elimination of anisotropic properties in tubes, control of the size of dispersoids etc. An attempt has been made to produce nano-oxide ODS alloy tubes through a collaborative effort of several research laboratories and production units. In this lecture, the development and characterization of nano-oxide strengthened 9Cr Ferritic-Martensitic steel tubes are presented.

This event is part of the eventgroup INT Talks

Homepage
https://www.int.kit.edu/events.php

Speaker
Prof. K. Bhanu Sankara Rao

Mahatma Gandhi Institute of Technology, Hyderabad, India
http://www.uohyd.ac.in/index.php/services-and-facilities/central-instruments-laboratory/156-academic

Organizer
Dr. Christian Kübel
Institute of Nanotechnology (INT)
Karlsruhe Institute of Technology (KIT)
Eggenstein-Leopoldshafen
Mail: christian kuebel ∂does-not-exist.kit edu

Targetgroup
Interested / Everyone