Gm Global Technolgoy Operations, Inc.

Worcester Polytechnic Institute

Richard D Sisson

Qigui Wang

Loutfallah Georges Chedid

Makhlouf M Makhlouf

Bowang Xiao

Yiming Rong

Gang Wang

A method to predict heat transfer coefficients for metal castings during quenching and/or cooling is provided. First, an initial set of HTC data are obtained from the computational fluid dynamics (CFD) simulation based on the metal casting geometry, initial metal casting temperature (distribution), quench bed/tunnel dimensions and set-up, and a given or baseline (standard) quenching condition including, but not limited to, air and/or gas flow velocity, air and/or gas flow direction relative to the work piece, air and/or gas temperature, air and/or gas humidity, etc. The initial HTC values for the entire surface of the work piece calculated from CFD can then be optimized by multiplying scale factors to minimize the error between the predicted temperature-time profiles and the experimental measurements for the given or standard/baseline quench condition. When the HTC values are optimized for a standard/baseline quench condition, a set of semi-empirical equations (or weight functions) can be used to quickly modify the standard/baseline HTC data for different quenching conditions (i.e., variations of quenching conditions from the baseline) without performing complete heat transferring and optimization calculations. A system and article of manufacture are also provided.

Systems and methods for predicting heat transfer coefficients during quenching

An alloy solute sensor probe, measurement system and measurement method are disclosed for directly measuring solute concentration profiles in conductive material components at elevated processing temperatures. The disclosed device and method permit direct, real-time non-destructive measurement of solute concentration profiles in treated surfaces in alloy components. In disclosed embodiments, a novel concentric carbon sensor and rod-shaped carbon sensor are disclosed which employ AC frequencies for probing the subsurface region of alloy samples to determine carbon concentration profiles at steel surfaces from measurements of alloy resistivity profiles. Results of carbon profile measurements obtained with the disclosed device and method compare favorably with conventional destructive analytical measurements made on post-processed samples. The sensor probe and method may be utilized to determine solute concentration profiles with a variety of solute materials and alloy compositions and may be advantageously employed in alloy surface processing, carburization heat treatments, induction heating and fatigue fracture applications.

Real-time carbon sensor for measuring concentration profiles in carburized steel

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Worcester, MA, United States of America

Richard D Sisson