Reviewed during the first meeting of the Center for Heat Treating Excellence (CHTE) consortium, held 18-19 April 2000 at Worcester Polytechnic University, were four projects identified by member companies as the most critical topics facing the industrial heat treating community. The projects include control of distortion, quenching, aluminum solution heat treatment and development of an analytical tool for furnace loading. While these four projects were selected as top priority, they are only a small fraction of the total number of projects that were proposed to the Center for possible research funding.
The CHTE is a member-driven consortium fueled by the participation of industry and association members. Initially, over sixty proposals for various research topics were submitted by the consortium member companies. These sixty proposals were evaluated by a steering committee comprised of representatives from founding member companies and the four projects mentioned above were selected to receive funding for the first two-year period. The direction for each of the four research projects is guided by a research team and a focus group who are responsible for making sure the research efforts remain focused on the needs of industry. The objectives of each of the four projects are outlined below.
Understanding and Control of the Quenching Process: This project is intended to provide a detailed understanding of quenching fluids with the ultimate objective of developing a model to predict microstructures of quenched steels as a function of composition and quenching fluid performance. Key to reaching this objective is the creation of a database for the heat transfer coefficients for steel and aluminum alloys in a wide variety of quenching fluids. This data is to be used in the development of a predictive CFD model that will describe quenching fluid performance as a function of the fluid's physical properties.
Control of Distortion and Residual Stress: The objective of this project is to provide industry members with tools for the prediction/control of distortion and residual stresses. The project also involves the determination of factors needed for input into predictive computer models and to use these models to predict the behavior in two well-known materials - Inconel 718 and 4140 steel - with respect to distortion. The results will be correlated with the quenchant performance project.
Solution Heat Treatment of Aluminum Alloys: This project involves the expansion of the knowledge base and the current understanding of how solution heat treatment affects the structure and properties of complex aluminum alloys. The work involves an evaluation of best practices in aluminum processing along with the development of computational models for prediction of these structure/property relationships.
Development of an Analytical Tool for Furnace Loading: In this project, an analytical model is to be developed that will predict the temperature distribution in a loaded furnace under the action of heat radiation, convection, and conduction. It is hoped that the establishment of physical-mathematical models for the heat transfer process will accurately predict the temperature distribution so as to provide an improved basis for temperature control and optimization.
While it is too early to realize the benefits of these projects, the industrial applicability and objectives of the projects should be scrutinized carefully by all members of the heat treatment industry. The projects have been identified as critical, yet the objectives may not provide immediate returns to the industry. For example, the development of models may help to improve future material characteristics from a materials engineering aspect, but they will not specifically address the needs of industry to reduce processing time and increase productivity or efficiency. While the Center can provide the necessary manpower to search areas that would otherwise be left uncharted, time must be allowed for the benefits of these projects to take effect.
As an example, while a continued understanding of the effect of solution heat treatment on microstructure and service properties in aluminum alloys does increase the scientific knowledge about the materials, it does not address the need to produce these properties in the shortest possible time to allow aluminum component manufacturers to decrease work-in-process and increase production volume and efficiency. An increase of 2 ksi in tensile strength may be beneficial from a materials engineering perspective, however, this "benefit" may never be realized if the solutioning time must be increased by four hours stealing valuable production time. From the manufacturers perspective, it would be more beneficial to allow tensile strength to remain the same while working to cut production time in half. A database of microstructure/property relationships for rapid solution heat treating conditions (e.g., from minutes to hours, rather than hours to days) would be equally if not more significant to industry. It is essential that all aspects such as these be considered when determining future projects to be funded from industrial financial sources.