13th Annual International Federation for Heat Treatment & Surface Engineering (IFHTSE) Congress

Oct. 7-10, 2002

The conference held in Columbus, Ohio was attended by Graduate Students Aparna Varde, Makiko Takahashi, Shuhui Ma, Post Doc Fellow Mohammed Maniruzzaman and Prof. Richard Sisson, Jr.

Papers presented:

Characterization of the performance of mineral oil based quenchants using the CHTE Quench Probe System
Gas Quenching of Steels: An Analysis of the Effects of Gas Composition and of Steel Types - 4140 and 304
The Effect of Bath Temperature and Agitation Rate on the Quench Severity of 6061 Aluminum in Distilled Water
Web-Based Data Mining for Quenching Analysis

Characterization of the performance of mineral oil based quenchants using the CHTE Quench Probe System

Advisor:

R. Sisson

Student:

Shuhui Ma

Post Doc Fellow

Mohammed Maniruzzaman

Abstract

The performance of a series of mineral oil based quenchants has been investigated using the CHTE Quench Probe System and probe tips of 4140 steel to determine the cooling rate, heat transfer coefficient, Hardening Power (HP) and Tamura's V indices in terms of the pyhsical properties of quenchants; e.g. viscosity and oil start temperature. The Quench Factor, Q, in terms of the hardness of the quenched parts was also calculated. The lumped parameter approximation was used to calculate the heat transfer coefficient as a function of termperature during quenching. The results revealed that the maximum cooling rate increases with decrease in quenchant viscosity. As viscosity increases, Tamura's V is nearly constant, while the HP decreases. For the selected oils, cooling ability of quenching oil increases with the increase in oil operating temperature, reaches a maximum and then decreases. The heat transfer coefficient increases with the increase in hardening power and maximum cooling rate. As the viscosity increases, the quench factor increases, which indicates the cooling ability of the oil decreases since the higher quench factor means the lower cooling ability of the oil. The hardness decreases with the increase in quench factor.

Gas Quenching of Steels: An Analysis of the Effects of Gas Composition and of Steel Types - 4140 and 304

Advisor:

R. Sisson

Students:

Celine McGee, Jacyln McHugh

Post Doc Fellow

Mohammed Maniruzzaman

Abstract

The CHTE quench probe system was modified to test the quenching performance of a variety of different gases at atmospheric pressure. The test were performed with Argon, Helium and air at varying gas velocities. The quench probe alloys used in this study were 304 stainless steel and 4140 steel. The heat transfer coefficients were calculated from the experimental measurements of temperature as a function of time. The experimental results showed that helium produced the largest heat transfer coefficients, followed by air and argon. The data showed a dip in the cooling rate and, therefore, in the apparent heat transfer coefficient vs. temperature curve for the 4140 steel but not for 304. This dip was explained as being due to heat that is released as Austenite transformed to Bainite and Pearlite in this temperature range.

The Effect of Bath Temperature and Agitation Rate on the Quench Severity of 6061 Aluminum in Distilled Water

Advisor:

R. Sisson

Student:

Marco Fontecchio

Post Doc Fellow

Mohammed Maniruzzaman

Abstract

A CHTE probe-quenching system, employing a 6061 aluminum probe, was quenched in distilled water while varying bath temperature and the rate of agitation. Time vs. temperature data was collected during the quench by use of an ungrounded K-type thermocouple embedded inside the probe, while cooling rates were calculated. A Quench Factor Analysis (QFA) was also performed to quantitatively classify the quench severity. The data showed an increase in maximum cooling rate as bath temperature decreased and agitation level increased. In addition, it was found that at higher levels of agitation, there was also an incrase in the standard deviation of the cooling rate.

Web-Based Data Mining for Quenching Analysis

Advisor:

Richard D. Sisson, Jr.

Student:

Aparna S. Varde

Post Doc Fellow:

Mohammed Maniruzzaman

Abstract

A Web-based Data Mining tool called QuenchMiner^TM is being developed for the analysis of quenching data obtained from CHTE at WPI. QuenchMiner is incremental to QuenchPAD^TM, the existing Database System supporting the CHTE Quench Probe System. QuenchPAD^TM stores experimental temperature-time data for metal probes quenched in liquid and gas based quenchants. The data is used to compute cooling rates and heat transfer coefficients. QuenchMiner^TMis a user-friendly tool for querying and analysis. In addition to providing the features of QuenchPAD^TM on the Web for worldwide access, QuenchMiner^TM does decision making based on case studies and pragmatic knowledge. It utilizes the principles of Data Mining and Knowledge Discovery in Databases (KDD) for this purpose. It uses information from complex data types like graphs, pictures and tables, in addition to simple relational data types. It builds a Knowledge Base of Association Rules and paths for action. It computes suggested decisions in response to the user's scenarios in quenching. QuenchMiner^TM provides at-a-glance information for quick and easy analysis, and serves as a Decision Support System (DSS) in heat treating at CHTE. It sets the stage for an Expert System.

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Last modified: Nov 02, 2005, 14:53 EST