An Investigation of Hardenability Assessment Method for Air Quenchable Iron-based Alloys
Air Quenchable Iron-based Alloy Application
(Abstract)
November 20th, 2022
C Paul Qiao, Dan Tanguay, Jake Beavers, Joe Schreiner, Levi Kempka, Dominic Grillo,
L.E. Jones Company
Menominee, MI 49858
Air quenchable iron-based alloys have been commonly used for valve seat insert (VSI) alloys and some tool steel applications. Compared to oil and water soluble quenchant quenching processes, air quenching process is not only cost-effective and environmentally friendly but also easier to achieve desirable microstructures for some intended applications. Not like low carbon and low alloy steels that the hardenability can be measured by Jominy End-quench Test method, there is no standard test method for assessing the iron-based alloy containing substantially high alloying elements.
An investigation aimed for establishing a hardenability assessment method for air quenchable iron-based alloys was carried out at LEJ with alloys J120V, J130, and J160. J120V is similar to M2 tool steel which can be hardened with water based quenchant solution as well as pressured air. For wear and corrosion resistant grade alloys J130 and J160, high air hardenability is fully expected. The parameters of austenitizing temperature, heat soaking time at the austenitizing temperature, air pressure/flow rate, and quenching time were evaluated. A small number of standardization tests were conducted to reveal the repeatability of the test method. Dilatometry-assisted heat treatment simulation was also carried out. Microstructural examination with the air hardened and dilatometry simulated samples was conducted to correlate bulk hardness and microstructure.
Based upon the study, a basic hardenability assessment test method has been proposed for hardenability assessment of air quenchable wear and corrosion resistance grade iron-based alloy. The measurement results from air quenchability test can be used to assist adequate heat treatment design of air quenchable grade iron-based alloys to optimize their intended application performance.