Influence of Interparticle-spacing on Creep Rate in a 2.25Cr-1Mo Steel
1996 Volume 82 Issue 1 Pages 92-97
Details
1996 Volume 82 Issue 1 Pages 92-97
Base material and heat-affected zone (HAZ) material of 2.25Cr-1Mo steels, which had been treated to control the interparticle spacing between carbides, λ, were subjected to creep tests under a stress of 108 MPa at 923 K to clarify the correlation between interparticle spacing between carbides and secondary creep rate. On the basis of the test results, the influence of interparticle spacing on secondary creep rate was evaluated. The results of this study are as follows:
(1) The correlation between the interparticle spacing, λ/m and Larson-Miller parameter, LMP is expressed by the following equation:
In λ=1.0 × 10-3 LMP -37
(2) The correlation between the interparticle spacing, λ/m and the minimum creep rate, εm/s-1 is expressed by the following equation:
Inεm=1.8In λ+b
where b is 15 for base material and is 12 for HAZ material.
(3) Using the creep strain curve obtained by the calculation on the basis of change of interparticle spacing during creep deformation, the creep life of the steel is estimated with an error of about 15%.
