| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an underground embedded object protection board capable of increasing hard machinability performance and impact resistance performance to further firmly protect a pipe line or the like embedded under the protection board, and having excellence in workability in the protection board placed on a cable and the pipe line or the like embedded in the ground. <P>SOLUTION: Alloy white cast iron formed by finely dispersing spherical carbonized vanadium is used in a martensite texture, a large number of projections 12 each having a curved exterior surface with a predetermined thickness are arranged on a rectangular plate surface in a zigzag arrangement and, while grooves 18 and 18 formed upward in extended directions of side sections 16 are formed in two rectangular side sections 16 and 16 adjacent to each other, downward projected strips capable of being engaged with the grooves 18 are formed on other two sides 20 and 20 adjacent to each other in extended directions of the sides 20 to form the underground embedded object protection board 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
