Hot Rolled Steel Plates, Sheets and Coils

Ramor Product of RUUKKI STEEL
Customers are seeking extreme protection and safety performance for their end-products. Ramor plate has excellent ballistic properties in combination with high hardness and strength. Ramor is developed for applications, where blast protection or high ballistic resistance is required.

Applications
• Doors, window frames, walls
• Bank counters and vaults
• Money exchange offices
• Cars, security vans
• Secured containers
• Shooting gallery devices
• Military vehicles and equipment

Description of the steel grades

Ramor armour steels are manufactured with a novel direct quenching process. With this method not only a good blast and ballistic protection is achieved, but also good flatness, surface quality and dimensional accuracy are obtained.
Ramor 400 steel is designed to give protection against high pressures caused by explosions and blasts.
Ramor 500 is the most suitable choice, when protection is needed against kinetic energy projectiles i.e. ballistic performance.
The number of the designation indicates the average Brinell hardness value 400 and 500 HBW, respectively.

Product forms

Heavy plates and cut lengths (=sheets).

Delivery condition

Quenched.

Dimensions

Heavy plates 6.0 – 30 mm.
Cut lengths with mill edges 2.5 – 6.5 mm.

Tolerances Heavy plates

Thickness, Table 1.
Width and length EN 10029.
Flatness EN 10029 class N, steel type H.

Cut lengths

Thickness, Table 1.
Width and length EN 10051.
Flatness EN 10029 class N, steel type H.

Surface condition

According to EN 10 163-2 Class B Subclass 3.
Repair welding of plates is not permitted in plate produc- tion of Ramor steels.

General technical delivery condition

According to EN 10 021. Unless otherwise agreed, inspection document EN 10 204-2.2 is issued in English.

Chemical composition

The chemical composition is stated in Table 2.

Mechanical properties

Typical mechanical properties are presented in Table 3.
the plate must take appropriate precautions to protect themselves and no outsiders must be allowed in the area. The safest location is usually by the bending ma- chine. The handling instructions of the steel supplier and safety instructions of the workshop must be adhered to in detail. New employees must receive appropriate train- ing before they are allowed to process hardened steels.

Materials testing

Materials testing procedure is presented in Table 4.
Recommended minimum plate thickness of Ramor 500 for different protection classes is presented in Table 5.

Heat treatment

Heat treatment is not recommended. If tempering process is needed, please, contact technical customer service for further assistance.

Welding

Ramor steels can be welded with common welding methods. Austenitic steel welding consumables are rec- ommended. Ferritic welding consumables can be used also, if the strength of the joint is important. If ferritic consumables are used, the need for elevated working temperature has to be studied in order to achieve fault- less weld joint.

Bending

When cold forming Ramor 500 steels by bending, the minimum bending radius of the upper tool has to be 8 times the thickness of the material. The correspond- ing bending radius for Ramor 400 has to be 5 times the thickness of the material. Special care has to be taken to the working safety, when these steels are cold formed. Mechanical cutting is not suitable as an edge preparation process for bended parts.

Cutting

Ramor steels are well suitable for laser and plasma cut- ting. Mechanical cutting can also be used, if the cutting shears/blades are hard enough and the equipment used is rigid. However, water jet cutting is preferred, because with this method the ballistic properties of the cut edge can be obtained.

Machining

Ramor steels can be machined using rigid hard metal tools and rigid equipment. Sufficient lubrication has to be provided and special attention has to be paid to clamping of work piece. The cutting parameters should be chosen in the way that the vibration of the cutting tool and the work piece can be avoided, because vibration decreases the lifetime of the cutting tool considerably.

Occupational safety

Special care must be taken in all stages of handling of hardened steels. Flanging is challenging due to the high strength and high flexural stresses of the plate. If the bending radius, for example, is too small and a crack is created in the bending point, the plate may fly from the bending tool in the direction of the bend. Those bending

Ramor. Heavy plates and sheets. Thickness Tolerances.

Lower thickness tolerance for both plates and sheets is 0 mm.

Chemical composition

Content %, maximum (cast analysis)

The steel is aluminium-killed and grain-refined.

Mechanical properties, typical

The typical impact strength values are results of the Charpy V impact tests in accordance with EN 10045-1. The value 20 J means tests carried out with 10 x 10 standard test pieces. When testing thicknesses less than 10 mm, the width of the test pieces corresponds with the plate thickness and the impact strength values decrease in direct relation to the surface area of the test piece.