Removing blued metal

[jimcaron]

Originally Posted by Justin Julian

I've always read that it takes 1,450 F to truly "anneal" steel. The reference to the 700-1,000 degree range is more likely relevant to the temper of the steel.

you;re right, sorry, I was thinking "C" and typed "F" by mistake.

nice catch

[edgarspencer]

As others have said, the temperature used in hot bluing is well below the lower critical temperature, and won't alter the grain structure or surface harness. Temperatures used in either a tempering cycle, or annealing cycle are really about the same. The difference is in the rate of cooling from those temps. I don't know enough about the chemical or mechanical reaction to the hot bluing process, and only know I don't like it.