Ultra-high-strength steels

Description

Ultra-high-strength steels have been in use for only a few years since grades with a tensile strength of over 700 N/mm² are, for the most part, not yet available in a constant quality. Categories include the following:

Dual phase (DP) steels
Dual phase steels belong, like TRIP steels and complex phase steels, to the multi-phase steel category. Designation: DP 500, DP 600, DP 800, DP 1000 (in development)

Complex phase (CP) steels
As compared to DP steels, CP steels demonstrate a significantly higher tensile yield strength at the same tensile strength.  Currently only CP 800 is available. Designation: CP-W-800, CP-W-1000 (in development)

TRIP steels and/or residual austenitic (RA) steels
Transformation Induced Plasticity (TRIP) steels demonstrate extreme work-hardening characteristics (conf. easily formable steels, bake-hardening).  This has the advantage of better formability in conjunction with greater component strength.  A disadvantage has been noted in that a very undefined distribution of strength is applied through the component which, in turn, can result in undefined resilience (spring-back). Designation: TRIP 700, TRIP 800 (in development)

Martensite phase (MS) steels
Martensite phase steels have high basic strength and are extremely difficult ot form.  It is used mostly for side impact elements that are more or less""bent"" rather than formed. Designation: MS-W-1000, MS-W-1200