Effect of potential factors in manufacturing process on mechanical properties of F82H

Abstract

A DEMO reactor requires over 3500 tons of reduced activation ferritic/martensitic steel. To prepare such a large quantity of the material with appropriate mechanical properties, it is important to study the effect of various factors in the manufacturing process for mass production. In our work, we focused on the effects of hot forging and the cooling method after normalizing, which have not been previously studied. Plates with three different thicknesses were fabricated from slabs with two different hot forging reduction ratios, and the tensile and Charpy impact properties were evaluated for each of these plates. The plates made using a lower hot forging reduction ratio had different tensile properties, and inhomogeneity and anisotropy were observed in the Charpy impact test results. These results indicate that the hot forging operation to which the ingot is initially subjected must be sufficiently high to ensure that the appropriate mechanical properties are achieved. To test the effect of the cooling method, plates cooled in air and those quenched in water after normalizing were prepared, and tensile and Charpy impact tests were performed on these plates. No significant differences were observed indicating that air cooling is sufficient to obtain the appropriate mechanical properties.