Harvey process

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A process of hardening the face of steel, as armor plates,invented by Hayward A. Harvey of New Jersey, consisting in theadditional carburizing of the face of a piece of low carbon steel bysubjecting it to the action of carbon under long-continued pressureat a very high heat, and then to a violent chilling, as by a spray ofcold water. This process gives an armor plate a thick surface ofextreme hardness supported by material gradually decreasing inhardness to the unaltered soft steel at the back.