Given:
At 140 MPa value of the Larsson-miller parameter is 24 x 10^{3}
T (20+log t_{r} ) = 24 x 10^{3}
1073 (20+log t_{r }) = 24 x 10^{3 }
20+log t_{r }= $\frac{24\times {10}^{3}}{1073}=22.367$
log t_{r} = 2.367
t_{r} = (10)^{2.367}
t_{r} = 232.91 h or 9.7 days