YES. Two ways to go. AFTER it has been tempered, after being hardened. Simple way but has to be done with care. Determine the apex of the warp. Polish to where you can see heat colors on the steel. With the blade in a vise, use a common propane torch and heat the blade at, and a little fore and aft of the warp apex to a dark blue or even on to gray, at the spine only. Do not allow the colors to run to the edge area. Over straighten a tad bit with a gloved hand and pour water over it until cool. You may have to repeat or adjust back if you over do it. The safer way is to lock the blade over straight on a thick piece of steel with C clamps. If necessary, you can put a penny or washer between the two pieces in order to get slightly over straight. Then run another temper cycle. Repeat if need be. This can be done multiple times if necessary with no change in the original temper.
