Faculty Advisor

Yiming Rong

Faculty Advisor

Richard D. Sisson, Jr.

Faculty Advisor

Diran Apelian

Faculty Advisor

Makhlouf M. Makhlouf

Faculty Advisor

Keyu Li

Faculty Advisor

Qigui Wang

Identifier

etd-041310-122535

Abstract

Aluminum and steel components are usually quenched in forced gas, oil or water flow to improve mechanical properties and improve product life. During the quenching process, heat is transferred rapidly from the hot metal component to the quenchant and the rapid temperature drop introduces phase transformation and deformation in the hot metal component. As a result, quenching problems arise such as distortion, cracking and high tensile residual stresses. To avoid or minimize these problems while improving mechanical properties, process optimization is needed for both part geometry and quenching process design. A series of methods, including four existing methods and two new methods developed in this dissertation, were applied to obtain accurate thermal boundary conditions, i.e., the heat transfer coefficient (HTC) distribution. The commercially available material model DANTE was applied with finite element software ABAQUS to model the phase transformations and constitutive behavior of steel parts during quenching. A user material subroutine was developed for aluminum alloys based on a constitute model and tensile test data. The predicted residual stresses in the quenched parts agreed with those measured using the improved resistance strain gauge hole-drilling method and other methods, which validates the numerical models.

Publisher

Worcester Polytechnic Institute

Degree Name

PhD

Department

Manufacturing Engineering

Project Type

Dissertation

Date Accepted

2010-04-13

Accessibility

Unrestricted

Subjects

experimental, CFD, finite element, residual stress, material modeling, heat transfer, quenching

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