The effect of coefficient in swift’s law, F and n values in Fig. 7, and
intensity of residual stress on the optimum pressure Po is shown in
Table 3. The intensity of residual stress was evaluated by the maximum
valuersmax, the definition of which was shown inFig. 6. Some
correlation between F value and Po seem to exist. The results was
rearranged in terms of the relationship between the proof stress
and the optimum press pressure as shown in Fig. 13 taking the
maximum tensile stress generated by the laser rsmax as a parameter.
The optimum contact pressure Po and the proof stress and
1% proof stress 1% show a strong correlation. It is revealed that
the optimum press pressure Po is roughly proportional to 1% proof
stress 1%, and the proportion ratio Po/1% was 110–120% regardless
The intensity of the residual stress slightly affects the optimum
pressure Po. The optimum pressure Po increased by just 10% when
the maximum residual stress rsmax increased from 190 to 280 MPa.
For that reason, it is revealed that the optimum press pressure Po
is roughly proportional to 1% proof stress 1%, and the proportion
ratio Po/1% was about 120%.
T