Grain growth during heat treatment has a negative effect on fatigue. As a result, grain growth kinetics have been determined for 4140 steel in order to predict the effective time for heat treating. A series of samples were heat treated at 850 oC and 900 oC and held for 60, 120 and 180 minutes. It was experimentally determined that grain growth kinetics were faster for samples with a higher austenizing temperature. Diffusivity growth constants were found to be 2.682E-06 (mm2/min) for the samples heated at 900C and 1.902E-06 (mm2/min) for those treated at 850C. The maximum heating time before the deterioration of the material properties, namely fatigue, was calculated to be 510min at 850oC and 442min at 900oC.

• This report represents the work of one or more WPI undergraduate students submitted to the faculty as evidence of completion of a degree requirement. WPI routinely publishes these reports on its website without editorial or peer review.

Creator

• McPherson, Omari

Publisher

• Worcester Polytechnic Institute

Identifier

• E-project-042508-223025

Advisor

• Sisson, Richard D.

Year

• 2008

Date created

• 2008-04-25

Resource type

• Major Qualifying Project

Major

• Mechanical Engineering

Rights statement

• In Copyright