Rephosphorized Steels

A rephosphorized steel is any steel that exhibits a capacity for a significant increase in strength through work hardening during part formation. This steel will not achieve any increase in strength from a thermal cycle and is therefore referred to as non bake-hardenable. Rephosphorized steels are made in the following grades. Users can find more specific material property information about these grades by following the links provided.

	180A
	210A

In order to increase initial strengths, solid solution strengthening elements such as phosphorus, manganese and/or silicon are added to the nominal chemistry. The amount of additional strength from work hardening will depend on the amount of carbon remaining in solution, which is controlled through chemistry and thermo-mechanical processing. Columbium, vanadium or titanium may be used in small quantities, but they will reduce ductility.

A combination of relatively low yield strength prior to manufacturing and a high in-part strength after forming makes rephosphorized steels good candidates for applications where dent and palm printing resistance is important. This material can be used in relatively deep draw or stretching operations. Due to the high in-part strength, rephosphorized parts are also good candidates for downgaging, which is important for weight reduction efforts.

When using rephosphorized steel, the amount of strain introduced during the forming process will largely dictate the final strength of the part. Since automotive parts, specifically exposed body panels, have a wide array of designs, there will be a corresponding disparity in the amount of strain introduced in these varying geometries. As a result, when using rephosphorized steel, it is important to design an adequate amount of strain into a part in order to fully utilize this material’s dent resistant characteristics.

• Weldability – Low carbon level makes rephosphorized steel a good welding candidate.


• Fatigue Performance – If used properly, rephosphorized steels have a high yield strength after forming, which means it will have a good resistance to fatigue.


• Denting – Rephosphorized steels were designed for dent resistance.


• Applications – Rephosphorized materials provide customers with a material that is capable of reducing the amount of dents and dings found on today’s cars. These materials have the formability requirements needed to produce most exterior applications. These exterior parts benefit from the work and bake hardening kicks that are experienced during processing. These parts include doors, deck lids, quarter panels, fenders, hoods and roofs.

Typical Properties for 180A MPa: (Back to top)

Typical Properties for 210A MPa: (Back to top)