11TH INTERNATIONAL SYMPOSIUM ON EXPERIMENTAL METHODS FOR MICROGRAVITY MATERIALS SCIENCE: Session II

NOT AVAILABLE 11:00 AM RAPID PREDICTION OF TIME-TEMPERATURE-TRANSFORMATION DIAGRAMS OF LOW AND MEDIUM CARBON MULTICOMPONENT ALLOY STEELS BY A COMPUTER EXPERT SYSTEM: Zhenbo Zhao1; Derek O. Northwood2; Cheng Liu3; Yunxu Liu3; Qihui Zhu3; 1University of Windsor, Mech. & Mats. Eng., 401 Sunset Ave., Windsor, Ontario N9B 3P4 Canada; 2Ryerson Polytechnic University, Eng. & Applied Sci., 350 Victoria St., Toronto, Ontario M5B 2K3 Canada; 3Jilin Institute of Technology, Mats. Eng., 76 Yanan Dalu, Changchun, Jilin 130012 PR China A computer expert system for the rapid prediction of time-temperature-transformation (TTT) diagrams of low and medium carbon multicomponent alloy steels was established. The principle and methodology for the rapid prediction of TTT diagrams were described. Some critical points of transformation used to model the time-temperature-transformation diagrams of muticomponent alloy steels were represented as functions of alloy chemistry. The bay between the two C-curves (pearlite and bainite), as a function of alloy chemistry, can be predicted accurately in terms of the precise calculation of Bs temperature (a new equation of Bs temperature has been proposed). It is believed that the reasonable prediction can be achieved in much larger concentration ranges. The limitations of alloy chemistry in most of other models can be avoided effectively because a relatively larger range of alloy chemistry (Ni, Mn, W, Mo, Cr, Si, V, Co, Cu) were considered in most equations. The commercial application potential in the design of new multicomponent alloy steels was discussed also. 11:20 AM THE EFFECT OF CU ON PHASE TRANSFORMATIONS IN LOW CARBON STEELS: Shaun Dilney1; Matthias Militzer1; 1The Centre for Metallurgical Process Engineering, University of British Columbia, Vancouver, BC, V6T 1Z4 Canada Increases in the level of residual Cu in steel scrap is forcing electric arc furnace steelmakers to process steel containing higher levels of Cu. Although Cu can be detrimental during processing, causing hot shortness, it can also be a beneficial alloying element, improving mechanical properties through precipitation hardening and grain size refinement. The aim of this work is to investigate the effect of Cu on the phase transformation kinetics of low carbon steels, containing 0.05wt% to 0.8wt%Cu. The austenite decomposition kinetics has been investigated with continuous cooling tests using a dilatometer and a Gleeble 1500 thermo-mechanical simulator. The study emphasizes the cooling conditions of a hot strip mill run-out table. Based on the experimental results, a model is proposed which accounts for the effects of composition, cooling rate, and austenite grain size on the austenite-to-ferrite transformation kinetics, the resulting ferrite grain size and the mechanical properties. HIGH-TEMPERATURE SUPERCONDUCTORS: SYNTHESIS, FABRICATION AND APPLICATION: Applications & Tape Fabrication Sponsored by: Electronic, Magnetic & Photonic Materials Division, Structural Materials Division, Superconducting Materials Committee Program Organizers: U.Balu Balachandran, Argonne National Laboratory, 9700 S. Cass Ave. Bldg. 212, Argonne, IL 60439 USA; Pradeep Haldar, Intermagnetics General Corporation, 450 Old Niskayuna Rd., Latham, NY 12110 USA; Chandra Pande, Naval Research Lab, Mats. Sci. & Tech. Div., Washington, D.C. 203755000 USA Tuesday AM Room: 18 March 2, 1999 Location: Convention Center Session Chairs: Judith MacManus-Driscoll, Imperial College of Science & Technology, Centre for High Temperature Superconductivity, London, England SW7 2BZ UK; H. W. Neumuller, Siemens AG, Corporate R & D, Erlangen Germany 8:30 AM INVITED PAPER HIGH TEMPERATURE SUPERCONDUCTIVITY: PROSPECT FOR ELECTRONIC APPLICATIONS: Donald U. Gubser1; 1Naval Research Laboratory, Mats. Sci. & Tech., Code 6300, 4555 Overlook Ave., SW, Washington, D.C. 20375-5343 USA High temperature superconducting (HTS) films are of sufficient quality and size to permit system demonstrations of superconductivity for a variety of electronic applications. The most prominent device structures are the high Q filters. These filters are used in base stations for