| 摘要 |
PURPOSE:To obtain a quickly workable and durable die material economically by using, as the base material for die, a compound body made by unifying a surface metal consisting of high alloy tool steel and a base metal consisting of structural alloy steel. CONSTITUTION:Base material 1 for die is made by forge welding or brazing a surface metal over whole surface of a base metal forming a base to unify the two. In case where the surface metal is die steel, it is unified by forge welding. The process is carried out in the following sequence: heating, rolling forge welding (compounding and unifying), normalizing, annealing, hardening and tempering. After this, it is finished by grinding the upper and lower faces. For the base metal 2, steel having hardness of HR C20-40 after heat treatment is used to permit drilling and tapping. In case where the surface metal is high speed steel, the base metal 2 and surface metal 3 are usually compounded and unified by brazing though forge welding is sometimes used. At this time, brazing filler metal is inserted between the two, and hardening is performed at the same time. After brazing and hardening, it is tempered and upper and lower faces are finished by grinding to obtain a base material 1 for die. |
