hello, please it's extremely urgent
i did this test f shot peening:
cast shot iron S330, hardness=490HV
target hardness 498HV
after that i measured the microhardness of the target i found that it decreas 460HV????????
can you explain that to me , i cant find any one for the moment it 's really strange!!!!!!
pleaaaaaaaaaaaaaaaaaase
and thank you very much
