Effects of Alloying Additions and Material Structures on the High Accuracy of the Predictive Law of Creep Crack Growth for W Strengthened 9-12%Cr Ferritic Heat Resistant Steel

Abstract

  The life of creep crack growth for W strengthened 9-12%Cr steel is sensitive to the alloying additions and material structures, such as lath martensitic structure and grain size caused by inhomogeneous cooling rate in steel ingot during the manufacturing stage, which results in the large scattering of experimental data from the law of creep crack growth life.
   In this paper, creep crack growth tests were conducted using W strengthened 9-12%Cr steels with various contents of alloying additions and the dimensions of micro-nano structures. The effects of the composition of alloying additions and material structures on the life of creep crack growth for W strengthened 9-12%Cr steel were clarified.