Guide To Purchasing 2507 Stainless Steel Rods For Pressure Vessels

European Chemical Equipment Manufacturer Specializing in Chlor-Alkali Reactors and High-Pressure Piping

Project Requirement:
Supply of 500 cold-drawn stainless steel bars made of grade 2507 (diameter: 80 mm, length: 6 meters) for a chemical plant in Spain. The material will be used for manufacturing pressure vessels that handle chloride ion (Cl⁻)-containing media.

Compliance Requirements:

EU Pressure Equipment Directive (PED 2014/68/EU): CE certification required. Material certificates must be provided in accordance with EN 10204:2018 Type 3.1/B, certifying compliance with the chemical composition and mechanical properties specified in EN 10088-3:2014.

Welding Procedure Compliance: The bars will be machined into support shafts for the pressure vessels. All welded joints must meet EN ISO 15614-7 welding procedure qualification standards. Welders must be certified according to EN ISO 9606.

Corrosion Resistance: Materials must have a Pitting Resistance Equivalent Number (PREN) ≥ 40 to ensure durability in highly corrosive, chloride-rich environments.

 

Client Pain Points:
The client has previously experienced multiple project certification failures and a 2-month schedule delay due to suppliers' inability to provide complete and compliant documentation. They urgently require a one-stop, fully compliant solution.
Weld seams are subject to third-party non-destructive testing (UT), with defect classification to meet the acceptance criteria of EN 1090-2 (standard for welded structural steel components).

 

Gnee Customized Solution

CE Certification and Material Certification:
Gnee's facility is PED 2014/68/EU certified. For this project, we provide EN 10204:2018 Type 3.1/B material certificates clearly indicating the chemical composition: Cr 25.5%, Ni 7.2%, Mo 4.0%, N 0.26%.
PREN is calculated as: PREN = Cr + 3.3 × Mo + 16 × N = 25.5 + 3.3 × 4 + 16 × 0.26 = 43.26 (well above the required minimum of 40).
An SGS third-party spectrometry report is included to verify elemental consistency.

Mechanical Properties:

Tensile Strength: 850 MPa

Yield Strength: 600 MPa

Elongation: 28%
All values meet the EN 10088-3 standard for super duplex stainless steels.

Welding of 2507 Stainless Steel Bars:

Welding Process: GTAW (TIG welding)

Filler Wire: ER2594 (25Cr-9Ni-4Mo-0.3N)

Deposited Metal: Ferrite content approx. 50%, ensuring balanced duplex microstructure

Welding Qualification Report (PQR): In accordance with EN ISO 15614-7, covering parameters such as welding current (120–140 A), travel speed (8–10 cm/min), and interpass temperature (≤150°C). Verified by a third-party agency, confirming weld tensile strength ≥ 800 MPa, matching base material strength.

2507 Stainless Steel Rods Manufacturers