Quality	Standard	Possible coatings	Alloy concept
CR2	VDA 239-100	UC, EG, GI, GA, AS, ZM	Non IF or IF

Testing direction	Yield Point Re (MPa)	Tensil Strength Rm (MPa)	Elongation type 1 A50 (in %)	Elongation type 2 A80 (in %)	Elongation type 3 A50 (in %)	r 90/20	rm/20	n10-20/Ag
Q	140 – 240	270 – 370	≥ 35	≥ 34	≥ 34	≥ 1,3	≥ 1,2	≥ 0,16

Grade CR2, also known as deep-drawing grade, belongs to the group of mild steels defined in the VDA 239-100 standard. CR2 steels are characterized by their particular suitability for deep drawing processes and are therefore frequently used in the automotive industry and other industries that require complex components with high formability. Thanks to the excellent formability of CR2 grades, components with deep deformation and complex geometries can be reliably produced.

The surface of CR2 steels can be treated by various finishing processes for additional corrosion resistance and specific requirements. A common surface treatment method is electrolytic galvanizing (EG). In this method, a zinc coating consisting of at least 99.9% pure zinc is electroplated onto the surface of the steel. This gives the steel excellent corrosion resistance and a uniform coating thickness, which is particularly suitable for demanding exterior parts.

Another surface finishing process is hot-dip galvanizing with a zinc coating, also known as hot-dip galvanizing (GI). In this process, the steel is immersed in a molten zinc bath with a zinc content of at least 99%. This type of galvanizing provides a robust and uniform zinc coating that ensures high corrosion resistance even under heavy use.

There is also hot-dip galvanizing with a zinc-iron alloy coating, also known as galvannealing (GA). In this process, the steel is immersed in a zinc bath and then heat-treated so that iron diffuses into the zinc layer. The result is a uniform, matt gray coating with an iron content of typically 8 to 13%, which offers even greater strength and abrasion resistance compared to pure zinc coating.

An alternative finish is hot-dip coating with an aluminum-silicon coating (AS). In this process, the steel is immersed in a molten bath consisting of aluminum and 8 to 11 % silicon. This coating provides improved high-temperature resistance and is particularly suitable for applications that have to withstand high heat.

Finally, there is hot-dip coating with a zinc-magnesium coating (ZM), in which the steel is immersed in a zinc bath containing 1 to 2 % magnesium and 1 to 3 % aluminum. This zinc-magnesium coating combines the advantages of the corrosion resistance of zinc with the abrasion resistance and hardness achieved by the addition of magnesium and aluminum.

Thanks to the variety of finishing methods, CR2 deep-drawing steels can be optimally adapted to the requirements of their areas of application. The VDA 239-100 standard provides a sound basis for selecting a suitable material with specific forming and corrosion resistance. The CR2 grade is therefore an excellent solution for complex components that require both high formability and a protective surface finish.