Faculty Advisor

Sisson, Richard D.

Faculty Advisor

Yang, Mei


This report discusses the result of different austempering holding times and their effect on AISI 5160's properties. AISI 5160 samples were heated until they were entirely austenite and then submerged in a 600°F salt bath for 1, 2, 5, 30, or 90 minutes. The samples were then cut, ground, and polished using standard sample preparation methods for analysis using optical microscopy, scanning electron microscopy, and x-ray diffraction. Separate samples in the form of tensile testing bars were prepared similarly. Vickers microhardness, Rockwell hardness, and tensile testing were performed. Analysis showed an increase in bainite as the austempering time increased, reaching 100% composition after 30 minutes. Elongation increased with the holding time, while hardness decreased.


Worcester Polytechnic Institute

Date Accepted

April 2019


Mechanical Engineering

Project Type

Major Qualifying Project



Advisor Department

Mechanical Engineering