*3.2. Hardness Measurement*

The measured hardness values are collected in Table 2. The average hardness measured in the unpeened region, around 120 HB, is 34% higher than the nominal hardness reported by the manufacturer, which is a result of the milling operation used to cut the specimens. Comparing this to the measurements at the notch, it shows a hardness increase of about 50% after LPwC.


**Table 2.** Brinell hardness measurement results. LSP—laser shock peening.
