# Permeability and magnetization of soft iron at various fields

I'm curious as to the magnetic permeability of soft iron (and other materials if available) under different fields. I know permeability of materials changes with field (that is why we have saturation points). Has someone calculated this? Can I find a table or something somewhere?

It also seems to me that magnetization should not occur instantly. It seems that the B field should take time for a given H field to build up (i.e. it seems that it should take time for the domains to align). For my application I can assume that if magnetization occurs in around a microsecond that it is instant but if it takes even 10 microseconds this can have an effect. What does the rate of magnetization look like? Does it occur pretty quickly (low microseconds to nanoseconds)?