DIFENDER 400: High-Strength Quenched & Tempered Steel for Superior Ballistic Protection

It is preferably used for light weight armoured vehicles. Due to its performance the steel is used by the customers for civil and military protection systems.

The material can be formed by cold bending, in spite of its high hardness. It is recommended that the thermal cutting or shearing edges in the area of the bend should be grinded. The bending speed must be adjusted by the fabricator to the geometry of the processed parts.

Due to the high strength values of DIFENDER 400 in the quenched and tempered condition the spring-back phenomenon has to be taken into account while cold forming. During the processing, the necessary safety measures have to be taken, so that nobody will be exposed to a danger by a possible fracture of the work piece during the forming process.

If particular requirements, which are not covered in this material data sheet, are to be met by the steel due to its intended use or processing, these requirements are to be agreed before placing the order.

The information in this technical data sheet is a product description. This material data sheet is updated at irregular intervals. The current version is available from the mill or as download at www.dillinger.de.

DIFENDER 400 is delivered in a heat treatment condition which is ready for assembly. Subsequent heat treatment above 200 °C impairs its ballistic properties and is therefore not permissible.

DIFENDER 400 is suitable for machining. In view of its high delivery hardness a lower cutting speed must be anticipated.

DIFENDER 400 can be supplied in the following dimensions:

On request, other dimensions can be agreed.

The entire processing and application techniques are of fundamental importance to the reliability of the products made from this steel. The user should ensure that his design, construction and processing methods are aligned with the material, correspond to the state-of-the-art that the fabricator has to comply with and are suitable for the intended use. The customer is responsible for the selection of the material. The recommendations in accordance with EN 1011 should be observed. The much higher tensile properties of the armoured steel comparing to other steels covered by the standard can lead to a higher crack probability while processing.

The properties under ballistic impacts have to be agreed.

Surface quality: Unless otherwise agreed, the indications in accordance with EN 10163-2, class A3, apply.

Surface protection Upon request the plates can be shot blasted and / or primer coated with a product at the manufacturer’s choice. In case you wish the application of a shop primer, but you do not specify the shop primer in detail, Dillinger offers shop primers as standard: you will find more information in our brochure „Shot blasted and primer coated heavy plates“ (www.dillinger.de)

Ultrasonic testing: Unless otherwise agreed, indications be in accordance with EN 10160, class S2/E2 apply.

Determination of the mechanical properties in the delivery condition per plate as rolled in 1⁄4 plate width in accordance with ISO 404. The hardness test is carried out in accordance with ISO 6506-1. The tensile test is carried out on flat rectangular, transverse specimens in accordance with EN ISO 6892-1.

The impact test will be carried out on Charpy-V-longitudinal and transverse specimens in accordance with EN ISO 148-1.

The test results are documented in a certificate 3.1 in accordance with EN 10204. A bullet resistance test can be agreed upon.

Tensile testing on transverse specimens at room temperature

The heat input during welding and thermal cutting can lead to a decrease in hardness in a small area adjacent to or in the weld seam. This can have an impact on the bullet resistance properties of DIFENDER 400. The manufacturer is advised to take this into account in his design.

For width and length tolerances EN 10029 table 2 and 3 will apply.

Unless otherwise agreed, the flatness tolerances will be in accordance with EN 10029, table 4, steel group H. Smaller flatness tolerances may be agreed upon request.