Plates for =150 mm. thickness can be tested for hardness in a Jominy testing appts. comprising a refractory-lined, electrically heated oven with a vertical bore-hole to receive the sample to be tested. The lower end is sealed off by a cooled metal plate, and the front face of the cylindrical sample rests on this plate. The appts. determines structural changes that have taken place in the steel because of quenching and from this enables hardness characteristics to be determined.
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