Abstract: A hydrogen closed-cycle hardening unit is disclosed that consisting of a vacuum oven with an internal quenching and circulation system, adjusted to operate under a pressure of 2 MPa, fitted with conduits and valves for feeding and discharging of quenching atmosphere. The oven, fitted with a hydrogen and/or nitrogen inlet line and an operating gas outlet line, is connected to two conduits, between the conduits' valves, and, through these conduits, to a unit of two containers. The first container, which is connected to an external hydrogen source, contains a metal alloy absorbing hydrogen as a high-pressure hydride, while second container contains a metal alloy absorbing hydrogen as a low-pressure hydride. Both containers are connected by another conduit.

Abstract: A hydrogen closed-cycle hardening unit is disclosed that consisting of a vacuum oven with an internal quenching and circulation system, adjusted to operate under a pressure of 2 MPa, fitted with conduits and valves for feeding and discharging of quenching atmosphere. The oven, fitted with a hydrogen and/or nitrogen inlet line and an operating gas outlet line, is connected to two conduits, between the conduits' valves, and, through these conduits, to a unit of two containers. The first container, which is connected to an external hydrogen source, contains a metal alloy absorbing hydrogen as a high-pressure hydride, while second container contains a metal alloy absorbing hydrogen as a low-pressure hydride. Both containers are connected by another conduit.