Where I live we have been through three range fires in the last 10 yrs. I always wondered if it effected the strength of barbed wire due to the fire burning off the zinc coating and due to the fact I have around over four miles of fence to maintain not including the cross fencing. Apparently it doesn't effect the strength in this study.
http://fireecology.okstate.edu/files/engle-weir-2000.pdf
http://fireecology.okstate.edu/files/engle-weir-2000.pdf