Grade 304, 316 and austenitic stainless steel plates, valves, piping, tanks and vessels (pipes and valves greater than 8-in diameter and rated for 500 psi and tanks greater than 500 l)

1C116

VIII.A0.009

ANNEX III - CATEGORY 1 — SPECIAL MATERIALS AND RELATED EQUIPMENT

1C - Materials

EU Regulation No 267/2012

Maraging steels, usable in the systems specified in 1.A. or 19.A.1., having all of the following: a. Having an ultimate tensile strength, measured at 20 °C, equal to or greater than: 1. 0,9 GPa in the solution annealed stage; or 2. 1,5 GPa in the precipitation hardened stage; and b. Any of the following forms: 1. Sheet, plate or tubing with a wall or plate thickness equal to or less than 5,0 mm; or 2. Tubular forms with a wall thickness equal to or less than 50 mm and having an inner diameter equal to or greater than 270 mm. Technical Note: Maraging steels are iron alloys: a. Generally characterised by high nickel, very low carbon content and use substitutional elements or precipitates to produce strengthening and agehardening of the alloy; and b. Subjected to heat treatment cycles to facilitate the martensitic transformation process (solution annealed stage) and subsequently age hardened (precipitation hardened stage).