Cathodic protection systems protect subsea structures but generate hydrogen gas. This hydrogen can enter metals and cause embrittlement. The standard provides strict hardness and microstructural limits to prevent HISC. 3. Microstructural Control
: Defined as "ambient," which the standard interprets as temperatures up to 50°C (122°F) Target Systems
: "Ambient" conditions, explicitly defined as temperatures up to 50°C (120°F) .