| 摘要 |
PURPOSE:To prevent stress concentration at center part to axial direction of outer layer member and to make difficult-to-development of crack by fitting a shaft member arranging grooves for supplying coolant on outer peripheral surface of a barrel part into cylindrical outer layer member made of wear resistant material and executing solid phase junction. CONSTITUTION:The shaft member 32 is fitted into the outer layer member 31 and diffusion junction is executed to both with hot isostatic pressing treatment. On the outer peripheral surface of the barrel part in the shaft member 32, the spiral groove is arranged and plugged at the center part, and a first groove 33 for supplying coolant flowing from the center toward one end of the barrel part and a second groove 34 for supplying coolant flowing toward the other end, are formed. The coolant is at first supplied to the center part of the barrel part to particularly cool the center part heated with a slab. As the outer layer member 31 and the shaft member 32 are integrated by executing the solid phase junction (diffusion junction) with the hot isostatic pressing treatment, the gap is not formed and load is received to both members and the stress concentration is difficult to develop and the crack is difficult to develop. |
