Nissan just announced the expanded use of an Advanced High Strength Steel (AHSS) that has a tensile strength of 1.2GPa (= 1,200MPa = 175 ksi = 175,000 psi). This follows their initial announcement in October 2011.
Things we’ve learned:
- The complex microstructure consists of 2 hard phases and 1 soft phase.
- The scale of the microstructure is micron / submicron.
- A new welding process needed to be developed to accommodate the microstructure.
- This new grade of steel was developed jointly by Nippon Steel, Kobe Steel, and Nissan. (Nippon recently merged with Sumitomo Steel to form Nippon Steel & Sumitomo Metal Corporation)
- Nissan plans to use AHSS on up to 25% of all body parts.
This is a great technical achievement, but a bigger hurdle may have been in the collaborative alloy development approach: two steel competitors partnered with one of their customers.
How will this play out? Will the steel companies be allowed to supply the grade to other automakers? Will the steel companies be allowed to market the grade through their partners? Nippon has Joint Ventures with ArcelorMittal in the USA and Ternium in Mexico; Kobe has Joint Ventures with US Steel.