SIST EN 3552:2005

SIST EN 3552:2005 is the Slovenian adoption of EN 3552:2005 from CEN. It specifies requirements for aerospace clad sheet and strip made from aluminium alloy AL-P2618A in T6 or T62 condition, with thickness from 0.4 mm to 6 mm. The document brings together the material designation, composition limits, heat treatment, dimensions, mechanical properties, inspection items and the standards it relies on.

What does SIST EN 3552:2005 specify?

SIST EN 3552:2005 specifies the requirements for aluminium alloy AL-P2618A clad sheet and strip for aerospace application. The standard covers product form, thickness range, delivery condition, test directions and the key material properties that must be checked in supply and acceptance.

The document is organized around a short set of clauses and requirement tables. Clause 1 states the scope, Clause 2 lists the normative references, and the specification tables cover composition, production route, dimensions, heat treatment, mechanical properties, inspection and marking. That structure helps a buyer or quality engineer go straight from material identity to the acceptance checks that matter in production.

What are the key requirements of SIST EN 3552:2005?

SIST EN 3552:2005 is built around a specific aerospace aluminium product: AL-P2618A clad sheet and strip, rolled to 0.4 mm to 6 mm thickness. In practice, that means the standard is aimed at procurement and quality control for a narrow material class rather than general aluminium sheet.

Material designation and product form

The standard identifies the material as aluminium alloy AL-P2618A and specifies a clad product form, supplied as sheet and strip. It also states that the production method is rolled. For users, this fixes the product family and the manufacturing route they need to buy or verify.

Chemical composition

SIST EN 3552:2005 gives chemical composition limits for the base alloy and also for the cladding alloy, which is identified as aluminium alloy AL-P7072. This matters because aerospace sheet is controlled not only by overall alloy family but also by the chemistry of the core and the cladding.

Thickness and cladding requirements

For the thickness range 0.4 mm to 3 mm, the cladding thickness on each face is higher than for the thicker range above 3 mm up to 6 mm. The practical effect is that the supplier must control the clad layer differently depending on product thickness, and the purchaser can check that the delivered material matches the intended build-up.

Delivery condition and heat treatment

The document ties the delivery condition to heat treatment and water quenching, and it distinguishes use conditions T6 and T62. It specifies temperature ranges and times for the heat-treatment steps. In practice, this is the part that governs how the mill or processor produces the temper that is later confirmed on the certificate.

Mechanical properties

SIST EN 3552:2005 sets minimum proof stress Rp0,2, tensile strength Rm and elongation A50 values, with separate requirements for the two thickness ranges. The test direction is LT and the temperature is ambient. For acceptance testing, this tells the reader which orientation and which room-temperature property set to use when qualifying the material.

Inspection and product control

The standard points to EN 4400-2 for test samples, test pieces, external defects, batch uniformity, electrical conductivity, marking inspection, dimensional inspection and product qualification. This means the acceptance process depends not only on the material values but also on the general aerospace sheet and strip inspection rules in the referenced specification.

Note on heat treatment history

The document notes that repeated re-solution heat treatment is not recommended because of copper diffusion in the cladding and its effect on elevated-temperature properties. For users, this is a practical limit on rework or reprocessing of material that has already been heat treated.

What terms does SIST EN 3552:2005 define?

• AL-P2618A - The base aluminium alloy identified by the standard for the clad sheet and strip.
• T6 - A heat-treated condition used for the product, linked in the standard to solution treatment, water quenching and ageing.
• T62 - Another use condition covered by the standard, with its own heat-treatment schedule.
• WQ - Water quench, the quenching step after solution treatment.
• LT - Longitudinal-transverse test direction used for the mechanical test pieces.
• Rp0,2 - Proof stress at 0.2% offset, used as a minimum acceptance property.
• Rm - Tensile strength, used as a minimum acceptance property.
• A50 - Elongation measured on a 50 mm gauge length.

Who uses SIST EN 3552:2005?

SIST EN 3552:2005 is used by aerospace material manufacturers, processors and purchasers who specify or receive clad aluminium sheet and strip. It is also used by quality control and test laboratories that verify chemical composition, heat treatment, dimensions and mechanical properties. In practice, it supports purchasing, inspection and product qualification for aerospace aluminium supply chains.

Which standards are used with SIST EN 3552:2005?

• EN 4258 - Provides the general organization of standardization for aerospace metallic materials and the link between EN standard types and their use.
• EN 4400-2 - Gives the technical specification for aluminium and aluminium alloy wrought products, Part 2: Sheet and strip, and supplies the inspection and test provisions referenced by this standard.
• EN 4500-2 - Gives the drafting and presentation rules for aluminium, aluminium alloys and magnesium alloys material standards.

What does the SIST EN 3552:2005 document contain?

The document contains the scope and the normative references, followed by specification tables for the core alloy and the cladding alloy. It also contains the product form and thickness limits, the heat-treatment and delivery-condition information, and the mechanical property requirements split by thickness range.

It further provides the inspection items that are delegated to EN 4400-2, including test samples, test pieces, external defects, batch uniformity, conductivity, marking and dimensional inspection. A short note at the end addresses repeated re-solution heat treatment and its effect on elevated-temperature properties.