Abstract: A steel having high mechanical properties, characterized in that it has the following composition by weight: 12% to 25% Nickel; 7.4% to 20% Cobalt; 3% to 11% Molybdenum; 0.2% to 2.21% addition elements, the remainder being iron, the structure of the material including a combination of fine grains and ultrafine grains, the so-called fine grains having a grain size of between 1.2 micrometers and 3 micrometers and the so-called ultrafine grains having a grain size of between 0.2 and 1 micrometer, the proportion of ultrafine grains being between 55% and 65%, and a process for manufacturing the steel.

Abstract: A steel having high mechanical properties, characterized in that it has the following composition by weight: 12% to 25 % Nickel; 7.4% to 20 % Cobalt; 3% to 11% Molybdenum; 0.2% to 2.21% addition elements, the remainder being iron, the structure of the material including a combination of fine grains and ultrafine grains, the so-called fine grains having a grain size of between 1.2 micrometers and 3 micrometers and the so-called ultrafine grains having a grain size of between 0.2 and 1 micrometer, the proportion of ultrafine grains being between 55 % and 65 %, and a process for manufacturing the steel.

Abstract: A heavy metal penetrator with a high tungsten content incorporating a central part or core formed of an alloy comprising from 85% to 97% in mass of tungsten associated with additional metals and which is enclosed by a peripheral sheath made of a more ductile tungsten alloy than that of the core. The sheath of the penetrator is made of an alloy comprising 30% to 72% in mass of tungsten, the core comprising nodules of tungsten bound in a matrix of a gamma phase ?C associating tungsten with additional metals, the two gamma phases being continuously joined to one another with no transition zone.

Abstract: A heavy metal penetrator with a high tungsten content incorporating a central part or core formed of an alloy comprising from 85% to 97% in mass of tungsten associated with additional metals and which is enclosed by a peripheral sheath made of a more ductile tungsten alloy than that of the core. The sheath of the penetrator is made of an alloy comprising 30% to 72% in mass of tungsten, the core comprising nodules of tungsten bound in a matrix of a gamma phase ?C associating tungsten with additional metals, the two gamma phases being continuously joined to one another with no transition zone.