I agree with sberry on this. Except for small amounts trapped in rust or scale on the surface the steel, unless it is porous, steel has no water in it. Steel is produced at upwards of 2500 degrees and no water lives there. The condition you observe is caused by moisture in the warm air of your torch condensing in the colder air and on the colder surface of the steel. The dew point in your flame and in the surrounding air are different. We see this often in our work where we pour molten metal into metal moulds. We always preheat to eliminate the possibility of moisture as the moulds are iron and they rust which can trap moisture on the surface. Failure to preheat can result in a steam driven explosion that can give the worker a faceful of molten metal. Not a fun day, been there done that and don't want to try it again.---Meltedmetal