Header dies used for hot-heading of bolts - Tool steels

Header dies used for hot-heading of bolts - Tool steels - Fractography

Figure 1: Header dies used for hot-heading of bolts, made from chrome-moly-tungsten (H12) hot-work steel. At top: In an attempt to obtain increased wear—resistance, this die was heat-treated to higher hardness than the other two dies. Early failure of the die indicates that the hardness was too high for this service. Middle and bottom: These dies were discarded because of wear in the square cavities. Note that heat-checking is pronounced and that cracks are enlarging through the corners. This condition represents proper working level of hardness for these dies.

Defect name: Cracks
Record No.: 2936
Type of defect (Internal/Surface): Surface
Defect classification: Fractography
Steel name: Tool steel
Steel composition in weight %: No data.
Note: No data.
Reference: Not shown in this demonstration version.