I want to find the material constant C, m and Kth of high strength steel in Paris law, can you help me?

Paris law:da/dN=C(K-Kth)m Yield stress of high strength steel is over 460 Mpa here.  Kth is threshold stress strength factor.  I can only find that of mild steel in BS7910-2005 and ASTM and JSSC

12 December 2014 2,958 9 View