GM 980X-A Unique High Strength Sheet Steel with Superior Formability

Substituting high strength low alloy (HSLA) steels for plain carbon steel in strength limited automotive components could reduce weight and conserve steel. However, the poor formability of these steels has, in part, restricted their use in automotive applications. This paper discusses a simple treatment which transforms some commercially available 980X steels into a product with the following desirable mechanical properties: (a) Yield strength of 950X steels in the as-treated condition but equal to that of 980X steels after 2-3% deformation, (b) Tensile strength of 980X steels, (c) Superior formability, equal to or better than that of 950X steel in hot rolled gages, i.e., thicker than ∼2 mm (0.075″), and approaching that of plain carbon steel in cold rolled gages. This material, named GM 980X, could significantly increase the use of 980X steels in automotive applications.

Two commercially available 980X steels were evaluated in this study; one was vanadium strengthened and the other titanium strengthened. The vanadium steel appears to be better suited for this process than the titanium steel. Probable mechanisms for the observed changes in properties and the reasons for the different response of the two steels are suggested.