Any export increases of gun metal grade, high carbon steel should be a red flag these days to stateside corporations operating in war zones. Structural steel is a low carbon steel that has more 'give' and is easier to weld. It's obvious which is which.

In Sweden's case, however, even pre-war they were already exporting 40% of Germany's demand for raw ore which increased to 50% during wartime iirc. So Germany already had the infrastructure necessary to process the raw materials into steel, and at scale scale beforehand.

In modern warfare, those same foundaries would make easy aerial targets due to the massive heat output from the bessimer process required to make steel from raw ore.