steels are
usually reaustenitized, then quenched and tempered
after welding. These are relatively hardenable
steels that in their quenched-and-tempered
condition develop yield strengths well above 965
MPa (140 ksi). Weld metals usually cannot
develop acceptable combinations of strength and
toughness at these levels in the as-welded or
stress-relieved condition. Therefore, it is necessary
to reaustenitize and then quench and temper
the entire weldment after welding. These steels
are often referred to by their SAE designations
(for example, SAF 4140 and SAE 4340).