HIDA ACTIVITY ON P91 STEEL

The 9%-12% Cr-steels are strategic materials for new power plant and f or component substitution for plant life extension. One of these steel s, P 91 was included in the project BE-1702 (HIDA) to provide crack in itiation and growth data for the improvement and validation of procedu res for high-temperature defect assessment. The paper presents an outl ine of the testing programme and the initial results for P 91. In addi tion to uniaxial and static/cyclic creep crack growth tests on standar d fracture mechanics geometries, feature tests are also included in th e experimental programme. These consist of internally pressurised pipe welds, pipe bends and 4-point bend pipes, and C-shaped specimens. The majority of these tests are still ongoing. The static and cyclic load ing conditions are being employed to consider the range of creep/fatig ue interaction in this alloy. All tests are being conducted at 625 deg rees C.