We currently launched a new program in our shop that is hot forged with Gerdau ZF7B steel. We are having a real hard time getting the furnace (Surface Combustion Cast Belt) to run with an efficient temperature program. Currently we are running @ 1742° in front section, 1500° in the middle section, 1050° in the back section, all 3 zones have bottom burners with the same settings as well. The belt speed is @ 2.2 "/min, and loading with an electronic loader @ 1000 lbs/hr. We have tried raising the temps in Zone 2 (Middle Section) to 1600°, however we lose our ability to control the cooling curve in Zone 3 and have had some spotty high harndess. Zone 2 and Zone 3 both have a control cool sytem built in. We only run the control cool in Zone 3, with the burner not hitting high fire under 1400° we must shut the gas off on Zone 3, so the control cool still allows us to manage the temp. To my question... Has anyone had any experience with heat treating this steel? We have had a metallurgist from an outside vendor give us some advice on how to process. They have suggested we ran as follows. Z1 - 1742° Z2 - 1600° Cooling On Z3 - 1050° Cooling On Belt Speed - 3.2"/min Load Rate - 2000 lbs/hr We are very concerned that we may not be able to hold the required tolerance in Zone 3 and lose our cooling curve and end up with parts with high hardness again. Upping the belt speed is going to drop the pre-heat temp down drastically, however it should in theory push the temps up in Zone 2, and most likely Zone 3 as well even with the cooling system on. Any advice would be appreciated, i have been working with Heat Treat for 9 years now and have never struggled with any other steel the way we are with this mess. Thanks in advance.