A bend is caused by internal stress and the application of heat removes and/or alters the stress. As you have well documented all you have been doing is chasing the stress around.
For a 1" shaft heat will just give you problems. In general using heat starts to straighten starts for me at about 2 1/2" diameter. I do not remember the company name but while I was in Northern Italy a company was checking hardened shafts for bends. If they were not within specs they used a CNC straightening machine which applied very localized heat and then pressure like in a press. Afterwards they were checked again and if they still needed straightening back into the straightener they went up to 3 more times. After a total of four they were scrapped.
After some reflection I think the company was building both machines and had sample shafts from the customer. I have a vague memory of the shaft being used for a small CV joint assembly. It was probably 25mm or so at the largest diameter and 250 to 300mm in length.
In general I like Vinny's approach better than applying heat, but in any case there will be a high likelihood the shaft will bend again in roughly the same spot. Generally the bend will be worse the 2nd time around.
So if the shaft is 1" or less I may put some time & effort into straightening it. However not much time say 15 minutes to an hour depending on the complexity of the shaft and the cost/time issue of buying/making a new shaft.
For a 1" shaft heat will just give you problems. In general using heat starts to straighten starts for me at about 2 1/2" diameter. I do not remember the company name but while I was in Northern Italy a company was checking hardened shafts for bends. If they were not within specs they used a CNC straightening machine which applied very localized heat and then pressure like in a press. Afterwards they were checked again and if they still needed straightening back into the straightener they went up to 3 more times. After a total of four they were scrapped.
After some reflection I think the company was building both machines and had sample shafts from the customer. I have a vague memory of the shaft being used for a small CV joint assembly. It was probably 25mm or so at the largest diameter and 250 to 300mm in length.
In general I like Vinny's approach better than applying heat, but in any case there will be a high likelihood the shaft will bend again in roughly the same spot. Generally the bend will be worse the 2nd time around.
So if the shaft is 1" or less I may put some time & effort into straightening it. However not much time say 15 minutes to an hour depending on the complexity of the shaft and the cost/time issue of buying/making a new shaft.