Focusing on physical metallurgy and materials, Materials Week '97, which incorporates the TMS Fall Meeting, features a wide array of technical symposia sponsored by The Minerals, Metals & Materials Society (TMS) and ASM International. The meeting will be held September 14-18 in Indianapolis, Indiana. The following session will be held Monday morning, September 15.
Program Organizers: J.E. Morral, University of Connecticut, Storrs, CT; R.D. Sission Jr., Worcester Polytechnic Institute, Worcester, MA; M.J. Fischer, Surface Combustion, Inc., Maumee, OH
Room: 105
Session Chair: J.E. Morral, University of Connecticut, Storrs, CT
MODELING THERMODYNAMICS AND KINETICS OF CARBURIZING AND NITRIDING - A BASIS FOR SOUND PROCESS CONTROLS: J. Ågren, Royal Institute of Technology, Dept. of Materials Science and Engineering, Division of Physical Metallurgy, Stockholm S-100 44, Sweden
Abstract not available.
9:00 am
MONITORING CARBURIZATION IN ROTARY RETORT FURNACES: C.A. Stickels, ERIM, 4683 Freedom Dr., Ann Arbor, MI
Small parts, such as links for steel chain and rollers for roller bearings, are often carburized in rotary retort furnaces. Parts are continuously fed into one end of a tubular retort, and move through the slowly revolving retort, driven by a helical rib on the inside of the retort. The carburizing gas is introduced at the discharge end and is vented at the charge end of the retort. Thus, there are counter-current flows of parts and the carburizing atmosphere. The carburizing process can be described as one in which the carbon demand of the workload and the carburizing potential of the furnace atmosphere vary along the length of the retort. For purposes of computation, the furnace was divided into a series of zones, within each of which the carbon potential and the carbon demand were constant. For a given set of input variables (temperature, production, rate, atmosphere flow rate, inlet atmosphere composition, etc.) the variations in carbon demand and atmosphere composition from zone to zone can be found. Calculations show how the amount of carburization in each part varies as a function of a) the inlet atmosphere composition, b) the flow rate of the atmosphere and c) the production rate. The "answers" provided by the model are sensitive to values estimated for rates of reaction within the gas phase and at the surface of the parts.
9:30 am
ON LINE DIFFUSION CALCULATIONS: T. Guler, Thermovac Pty., Ltd., 27 Biby St., Tugun 42224, Queensland, Australia
This paper will present several examples of "Simulation and Process Registrations" supported by metallurgical results on sealed quench furnaces. It will show that the presently used oxyprobes and simple controllers are more or less an off-line monitoring system and that on-line diffusion calculation has rendered the current methods as obsolete and superceded.
10:00 am BREAK
Program Organizers: J.E. Morral, University of Connecticut, Storrs, CT; R.D. Sission Jr., Worcester Polytechnic Institute, Worcester, MA; M.J. Fischer, Surface Combustion, Inc., Maumee, OH
Room: 105
Session Chair: M.J. Fischer, Surface Combustion, Inc., Maumee, OH
NITRIDING PROCESS CONTROL TECHNIQUES: R. Fincken, Marathon Monitors, Inc., 3100 E. Kemper Rd., Cincinnati, OH 45241
Abstract not available.
11:00 am
A DISCUSSION OF UNIQUE APPLICATION USING CAR-CALC MODELING SOFTWARE: R.L. Houghton, Hayes Heat Treating Inc., 800 Wellington Ave., Cranston, RI 02910
CARB-CALC software can accurately predict case depths in low alloy steel. The carbon profile data created from CARB-CALC can be automatically loaded into AC3 software, which can accurately predict hardness results of hardened and tempered low alloy steels with uniform or non-uniform carbon distribution. Both software packages are available from Marathon Monitors, Inc. This paper describes several examples of predictive models as compared to the heat treatment results. Both CARB-CALC and AC3 were used in the process development stage. The heat treatments were performed in a vacuum carburizing furnace with integral oil quench. The applications chosen for discussion are unique, since either the material was a non-standard carburizing grade or the process had to yield an unusual case profile requirement. The modeling software proved to be a valuable tool in the process development of these heat treat applications.
11:30 am
ON LINE USE OF INTERACTIVE DIFFUSION MODELS FOR CONTROL OF CARBURIZING AND NITRIDING: J.G. Conybear, I. Liddell, Ispen Industries International, 3260 Tillman Drive, Bensalem, PA 19020
Abstract not available.
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