Stress-strain Curves from Self-fluxing Pellets Reduced with CO or H<sub>2</sub>

Compression tests of self-fluxing pellets were conducted at 300 K and high temperatures with prismatic test samples cut from the centre of pellets. Two types of pellets were used: one reduced with CO, and one reduced with H2. Prismatic-shaped specimens were fractured in a brittle manner during the compression tests at 300 K and 973 K. The fracture stress at 300 K of the specimen reduced with CO is nearly the same as that reduced with H2 while the fracture stress at 973 K of the specimen reduced with CO is higher than that with H2. They show plastic deformation at higher than 1173 K. The yield stress of both types of specimens is nearly the same at above 1173 K. Poisson's ratio varied during deformation, suggesting deformation mechanism changes as deformation proceeded. The strain distribution of a specimen deformed at 1273 K measured using digital image correlation showed plastic deformation accumulated near the pores. It is considered that not only the collapse of the pores but also the plastic deformability of the matrix itself influences the temperature dependence of the yield stress of pellets.