Design and Fabrication of Jominy End-Quench Testing Machine: Hardenability Evaluation of AISI-8620 Case-Hardening Steel

摘要

Metallurgists have long considered the hardenability evaluation because of its necessity in formulating the hardness penetration rate of alloys with reference to their cooling curves. In this work, we designed and fabricated a Jominy end-quench testing machine by following ASTM-A255, Standard Test Methods for Determining Hardenability of Steel, through computer-aided designing. Our design possesses the novelty of water recycling, cooling tower, water-level indicator, and facile interface, and it is compatible with the environment. A hardenability evaluation test of AISI-8620 case-hardening steel has been performed on the as-fabricated machine. The results confirmed that AISI-8620 achieved the maximum hardness of 43.6 HRC at its quenching end through water quenching. Metallographic studies reveal the formation of a sufficient amount of martensite and other microstructures such as retained austenite, bainite, sorbite, and pearlite.