Jominy end-quench test

Hardenability is so important that a simple test is essential to measure it. The Jominy end-quench test, though inelegant from a scientific standpoint, fills this need. A bar 100 mm long and 25.4 mm in diameter is heated and held in the austenite field. When all the alloying elements have gone into solution, a jet of water is sprayed onto one end of the bar (Fig. 12.3). The surface cools very rapidly, but sections of the bar behind... 

Hardenability, not to be confused with hardness, is the ability of a material to be hardened by a heat treatment. In steels, it is a measure of the ability to form martensite and is measured by the Jominy end-quench test. A Jominy bar is fashioned to AISI specifications... 

Determination of hardenability is accomplished by the standard Jominy end-quench test (Figure 11.12), from which hardenability curves are generated. 

Figure 11.12 Schematic diagram of Jominy end-quench specimen (a) mounted during quenching and (b) after hardness testing from the quenched end along a ground flat.

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