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Lesson 03·Process variants

Gas nitriding — the workhorse and its limits

How dissociating ammonia builds a case in a sealed retort, what the Floe 2-stage cycle actually does, and the difference between a controlled and uncontrolled gas nitride process.

9 min readLesson 3 of 12

A forge shop sends an H13 punch out for gas nitride. Three certificates come back. Certificate A documents 48 hours at 525°C, no atmosphere data. Certificate B documents 72 hours, a 2-stage Floe cycle, Kn setpoints by stage, and a target compound layer phase. Certificate C documents a plasma cycle. The difference between A and B is the entire subject of this lesson. A documents furnace time. B documents a controlled atmosphere with a target compound-layer thickness, a target phase, and a hydrogen sensor that proves both. On a low-stress part, A and B may produce identical service life. On a part that sees thermal cycling, impact, or a tight microstructural spec, A delivers whatever the retort produced that day.