No lecture intended. Just pointing out that soft steel is not molten at 2100.
OK, fair enough.
I suppose a good case can be made that high carbon steel (almost cast iron -- 1.9? 1.95% C) begins to get molten when temperature crosses the solidus around 2100, even though it isn't completely molten until after it passes the liquidus at a higher temperature.
But then I was only trying to guess what the author meant anyway.
Malleable is a somewhat subjective/relative term.
It just doesn't make sense to me to say that steel becomes malleable at 2100.