Andy would you be willing to explain in more detail what in your words "a recipe for several potential problems down the road" I am very interested in understanding the dynamics of steel.
Sure. I said cold bending is unnecessary because even the most simple means to apply controlled heat would be adequate for this small project. If you have the gear to cowboy a HT, you should be set.
The main problem of cold forming is the potential to greatly increase unequal stresses within the stock which result from distortions in the steel's lattice structure. As you continue to work, crystalline dislocations/atomic-level gaps in the lattice begin to form once the elastic yield point is exceeded. Eventually this will lead to micro fractures that can't be repaired by normalizing.
The consequences of this are tools that may snap at quench, even if using the most appropriate quench temps and medium, or unexpectedly fail during routine use. Or you may find blades that receive optimal HT but still have unpredictably weak chippy edges that are difficult to maintain in the geometry needed for the job. Thinking of field-sharpened scythes and bent paper clips here.
I hear you though in that cold forging has been going on a long time and sure you're aware that your O1 stock was likely cold rolled from the mill. Bending a hook blade cold would likely work out well enough but, considering the above, I choose not to take the risk. If you do form it cold, most here would probably suggest you take the time to normalize well before HT. This will "reset" the grain to be uniform throughout the working edge and also reduce/refine its size if done well. Huge stresses will still exist in the blade's steel, but they will be more balanced and hopefully serve, rather than hinder, performance.
Practical thoughts from a hack; since such small thin sections are springy and lose heat so fast, I simply heated one end of some ~1" round to forging temp, locked that up in my post vise and used a mallet to curl my blade over that radius in one "heat" of the big piece. I imagine that was faster, easier and healthier than beating on it cold but your mileage may vary. Hope this helps.
