Can I re-temper A514/QT100 for increased toughness

[CR100]

We are developing an automotive drive plate that requires a failry ductile and tough material. The volume on the project is fairly low, so we are constrained to typical readily available plate material. A514/QT100 plate meets exceeds our requirements, but the concern is that the hardness is too great. Our requirements are min 70ksi Yield 85ksi Tensile with an elongation of >25%.

Can this material be tempered again to increase its ductility/toughness at a cost of some yield and tensile strength?

 

[metengr]

Yes, but at a slightly higher tempering temperature. The specification calls for 1150 deg F minimum, check the mill certs for the actual tempering temperature. I would go 30-50 deg F higher in tempering temperature and same time.