js44 -
Good question. Let me first say that in my experience it is notoriously difficult to get hold of records of PQR's from OEMs. Having said that, I just looked and I found three in my files, all of which (9.5 mm thick) were bent to 180 and were satisfactory. In addition to these tensiles, hardness, macros and charpies were carried out. They were on fairly standard 12Cr materials though, which is the main material I'm familiar with.
The performance in a bend test may depend on the material, but will be an indicator along with hardness and tensiles of the correct tempering of the weld and HAZ, thereby indicating ductility. One of the functions of the bend test is to expose defects and inadequate ductile material. If a bend test failed before 180 was reached, I'd be looking to see what caused the failure - but it wouldn't necessarily be detrimental to service.
Ductility is an important factor to prevent defect growth in service, but one would hope that the appropriate NDT technique could find defects that were not acceptable fbefore entering service. Incidentally, there are other factors to consider - inadequate tempering may lead to microstructures that are hard and susceptible to stress corrosion cracking in service and this should be detected by the hardness test. Some blade materials are susceptible to temper embittlement - this is not detected by hardness but will be by impact testing.
Hope it helps...