Material Information: Steel

HSS (High Strength Steel) is a general term for steel material within a specific strength range.

The vehicles are built of different steel material, partly to optimize the body (impact safety, rigidity, fuel economy, etc.) and partly to make it as repair-friendly as possible. The steel material is classified into four different groups based on tensile strength, which is the force required to plastically deform the material.

• Mild steel (MS). Trade steel with highest tensile strength of 180 MPa.
• High tensile strength steels (HS). Steel with a tensile strength between 180 - 280 MPa.
• Very high tensile strength steels (VHS). Steel with a tensile strength between 280 - 380 MPa.
• Extra high tensile strength steels (EHS). Steel with a tensile strength between 380 - 800 MPa.
• Ultra High Strength steel (UHS). Steel with a tensile strength of more than 800 MPa.

Mild Steel. This category of steel is used where use of a stronger steel is not necessary.

High Strength Steel There are three main types of steel in this category:

• Phosphorus-alloyed steel obtains is increase in strength with the help of the alloy matter phosphorus.
• HSLA steel (High Strength Low Alloy) is a low alloy steel in which the steel obtains its increase in strength with the help of the alloy matter Vanadium, Niobium or Titanium.
• DP steel (Dual Phase) obtains its increase in strength through the thermal treatment that the steel undergoes during manufacture. Then a two-phase structure of ferrite (iron) and martensite (carbon) is formed. This steel loses its strength when exposed to temperatures above 300°C.

Extra High Strength Steel. This category contains both HSLA and DP steel, but the strength has been further increased with greater additions of alloy substances.

Ultra High Strength Steel. There are two main types of steel in this category:

• DP-steel. Here, strength has been further increased with an advanced manufacturing process and with higher additives of alloy substances.
• BORON steel obtains its strength through the use of the basic element boron and contains relatively large amounts of carbon. The plate profiles are formed heated between the die cutter and die cushion, where the material is also hardened. Due to its extremely high strength, it is difficult to straighten with good results. Grinding or plasma cutting is recommended when replacing BORON steel components. BORON steel welds well. It is not possible to galvanized BORON steel during the production process. It is therefore very important to rustproof these components extra thoroughly.