鋼塊を用いた空隙欠陥の閉鎖技術の開発

―欠陥閉鎖パラメータQ値を用いた操業改善―

抄録

In the manufacturing process of large forged steel products, internal quality must be improved by introducing stress and strain. The effect of the forging pass schedule on the consolidation behavior of internal defects can be evaluated using consolidation parameter Q-value calculated from the hydrostatic stress and the equivalent strain. In this study, we performed the actual steel ingot test to clarify the consolidation behavior and threshold of Q-value. Subsequently, the effect of the void distribution on the Q-value was investigated. The density distributions of initial defects were determined by solidification simulation calculation and the change in density distribution with increasing Q-value was investigated by forging simulation. After conducting this preliminary study, we report the result of verifying void closure using a tool for actual forging process design.