I got my grandpa's tools when he passed away and I found a square stock of crucible Rex 49 what I gather from my research is that it's tool steel I was thinking of making either a hot cut chisel or a knife from it has anyone forged this steel before and know any heat treat info like air, oil, water quench and tempering and what temp for how long ECT

Title edited to reflect common name of steel

If you’re forging a hot cut, I’d forge it out, let it air cool and call it good. 

High Speed Steel lathe tool bit, forget forging it. The heat treat procedure alone is enough to make one just use it for what it is. They make great parallels if you do not have a lathe.

What size is it?

 

I don't have a lathe it is 12" × 5/8 I might just do what ranchmanben says it's probably the hardest steel in my shop BC of the tungsten

That is around $80 of HSS, sell it or trade it off for something better. Here is forging and heat treat info.

https://www.crucible.com/eselector/prodbyapp/highspeed/cpm4hch.html

It also very brittle and if it is not done right it can become dangerous if it comes apart while you are using it.

TY biggundoctor I'd be willing to trade if it was good carbon stock1075-95, 15n20, even but I am new to this and don't know anyone around town so any offers would have to come from you guys

Personally I would keep it around just as it is. I have some that I use for spacers, parallels, etc.. For hot cuts, etc you can use old axles, jackhammer bits, etc. some have used mild since it is still harder than yellow hot steel. Anything heat treated will lose the edge hardness after being in contact with forging temp steel.

well actually  some high alloys steels have drawing temps around forging temps for many steels and so they don't loss much in hardness.

Of course they are much more expensive and much more picking about forging and heat treating and so not used as much.