The study of the brittle fracture resistance in fusion areas between RPV STEEL 15H2NMFA grade 1 and austenitic padding
The authors investigate the brittle fracture resistance of PRV 15H2NMFA grade 1 steel. The study used sets of small-sized specimens and a set of standard specimens. It is shown that, using sets of small-sized specimens in mechanical tests to determine the brittle fracture resistance of RPV 15H2NMFA grade 1 steel, it becomes possible to increase the test volume in each batch by 8 times without significant changes in the design of irradiation devices and, therefore, initial irradiation parameters, thereby substantially expanding the database of test results for statistical processing.
The paper demonstrates the need for large-scale process simulation of conditions arising in weld joint zones that are inaccessible for direct testing, such as: (1) the welding zone between the base metal and the corrosion-resistant coating metal, (2) the welding area between the weld metal and the corrosion-resistant coating metal, and (3) the fusion area between the base metal, the weld metal, and the anticorrosive cladding metal.
Process simulation of the metal of fusion areas up to 0.5 mm wide (each is 100 μm in size) with an experimental electroslag refined (ESR) ingot of up to 300 mm long with a similar microstructure and variable chemical composition makes it possible (1) to examine at least 1000 small-sized impact specimens with a continuous distribution of the content of chemical elements in accordance with a certain law; and (2) to test these specimens and determine brittle fracture dangerous zones across fusion areas between the base metal and the anti-corrosive padding metal in the initial state or after subsequent irradiation at a given fluence rate and temperature.
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