Comment by colechristensen

The important qualities of steel emerge out of microstructure: nanometer to millimeter sized features (several different crystal structures in the same material interacting through the boundaries between them and the bulk properties in them) which requires quantum interactions to be tracked through many orders of magnitude of scale. This includes how these different structures are formed though many stages of melting, tempering, work hardening, etc. In other words it is hideously computationally complex.

One of many fields where yes there is a lot of simulation and yes it is developing but still quite far from having anything close to a complete model which can escape the need for extensive experimentation.

There is a sort of prevalent idea among people outside these fields that simulations exist which can just handle anything. This is very wrong and quite far away.