Xianglong Guo

Microstructure and mechanical properties of (TiB+La2O3)/Ti composites heat treated at different temperatures

Abstract Near-α titanium matrix composites reinforced with TiB and La 2 O 3 were synthesized by common casting and hot-working technology. The effects of β heat treatment temperature on the microstructure and the tensile properties of the in situ synthesized (TiB+La 2 O 3 )/Ti were studied. Microstructure was studied by OM and TEM, and tensile tests were carried out at room temperature and 923 K, respectively. Results show that with the increase of β heat treatment temperature, prior β phase grain size increases and α colony size decreases. Room temperature tensile strength increases with the increase of β heat treatment temperature, which can be attributed to the decrease of α colony size with the increase of β heat treatment temperature. However, high-temperature tensile strength decreases with the increase of β heat treatment temperature and the decrease of the high-temperature tensile strength is due to the increase of the prior β phase grain size.

Corrosion and Stress Corrosion Cracking Susceptibility of Type 347H Stainless Steel in Supercritical Water

The corrosion resistance and stress corrosion cracking (SCC) susceptibility of Type 347H stainless steel (SS) in supercritical water (SCW) were investigated. The general corrosion behavior was inve...

Stress Corrosion Crack Growth Behavior of Type 310S Stainless Steel in Supercritical Water

Stress corrosion crack (SCC) behavior of Type 310S stainless steel (SS) in supercritical water was evaluated at 400°C to 550°C. Crack growth rates (CGR) were obtained as a function of temperature and corrosion potential. Results show that Type 310S SS exhibits 100% intergranular SCC, and creep plays an important role in the overall growth rate. The SCC CGR increases with temperature between 400°C and 550°C, and is higher at a medium-low corrosion potential (argon deaerated water) than in water with dissolved O2 or dissolved H2. A mechanism for SCC of Type 310S SS in supercritical water is proposed to explain the combined effect of SCC and creep.