|
In order to ensure the sustainable development of nuclear power, to further improve the safety of nuclear power, reliability, economy and preventing nuclear proliferation, countries have begun to study the fourth generation reactors, the biggest characteristic of the fourth generation of reactors operating temperature of the reactor is significantly increased . Increase the operating temperature inside the reactor to improve the thermoelectric conversion rate, the utilization of fuel economy and power, etc., but at the same time, so that the reaction temperature within the operating conditions of the piles are more complex, making the performance requirements of the material also more demanding, the fourth-generation reactor structural material must have high temperature oxidation resistance, creep resistance, anti-radiation and other excellent performance. Currently, the fourth generation of reactors have been identified structure has seven candidate materials are: nickel-base alloys, austenitic stainless steel, ferritic / martensitic steels, oxide dispersion strengthened (Oxide Dispersion Strengthened, ODS) steel, ceramic materials, refractory metals and graphite. In this paper, ODS PM2000 alloys and austenitic stainless steel 316L two kinds of candidate materials were related experiments. Experiment, PM2000 adopted after 1350 ℃ hot state and two states recrystallization heat treatment of the sample, 316L austenitic stainless steel with a solution treatment after 1100 ℃ taken after cooling, air cooling, oil cooling means cooling, and hot-rolled four kinds of samples, and water samples at 600 ℃ and 650 ℃ under the conditions of a sample after stretching. Experiments were used optical microscopy, transmission electron microscopy and EDX-dispersion was analyzed in different states of the two materials, microstructure and structure. PM2000 TEM sample in the test, we found that the precipitation of the dispersed particles of the material is 10 ~ 50 nm and more of the range, Al-Fe (Cr) oxide, Al-Y (Fe, Cr) oxide, Al ( Cr, Ti) oxides and Fe-Cr (Al, Ti) intermetallic precipitates and other four categories, which, Al-Fe (Cr) oxide was first discovered in the material precipitated phase, simultaneous contrast hot-rolled samples, and then crystalline sample, it was found, and then precipitation of the crystalline state compared to the sample of the hot-rolled much refinement. 316L in the study, we found four different states 316L austenitic stainless steel metallographic samples found in solution after the experiment, a number of the austenite grain growth, and there have been many matrix twinning organization; In water samples for tensile test after 650 ℃ the TEM experiment found, 650 ℃ tensile test occurs when weakened until the disappearance of sawtooth phenomena and the concentration of solute atoms.
|